diff --git a/Makefile b/Makefile
index 038b78c6..b58a7449 100644
--- a/Makefile
+++ b/Makefile
@@ -143,7 +143,7 @@ checkout-base-contracts-commit:
 ##
 # Task Signer Tool
 ##
-SIGNER_TOOL_COMMIT=db50e4234a5475a3f109e61a83fd047924916b41
+SIGNER_TOOL_COMMIT=43c55040fee45ec90a33400b10215f1756687ad7
 SIGNER_TOOL_PATH=signer-tool
 
 .PHONY: checkout-signer-tool
diff --git a/sepolia/2026-05-13-incident-multisig-signers/.env b/sepolia/2026-05-13-incident-multisig-signers/.env
new file mode 100644
index 00000000..f19c64a2
--- /dev/null
+++ b/sepolia/2026-05-13-incident-multisig-signers/.env
@@ -0,0 +1,15 @@
+# Required: Git commit hash for https://github.com/base/contracts
+BASE_CONTRACTS_COMMIT=8b5baf316c8dd1011b8b0dcfa9f6eac5a0f216e5
+
+# Network-specific addresses are automatically loaded from {network}/.env via include ../.env
+
+# Required: Address of the Gnosis Safe whose signers will be updated
+OWNER_SAFE=0x646132A1667ca7aD00d36616AFBA1A28116C770A
+SECONDARY_SAFE=0x6AF0674791925f767060Dd52f7fB20984E8639d8
+
+# Required: Address of a signer on OWNER_SAFE (used for simulation)
+# Must also match the sender defined in validations/base-signer.json
+SENDER=0x644d0F5c2C55A4679b4BFe057B87ba203AF9aC0D
+
+# Enable state diff recording for validation
+RECORD_STATE_DIFF=true
diff --git a/sepolia/2026-05-13-incident-multisig-signers/FACILITATOR.md b/sepolia/2026-05-13-incident-multisig-signers/FACILITATOR.md
new file mode 100644
index 00000000..24572b00
--- /dev/null
+++ b/sepolia/2026-05-13-incident-multisig-signers/FACILITATOR.md
@@ -0,0 +1,79 @@
+# Facilitator Guide
+
+Guide for facilitators managing the Sepolia Incident Multisig signer update.
+
+## Task Origin Signing
+
+After setting up the task, generate cryptographic attestations (sigstore bundles) to prove who created and facilitated the task. These signatures are stored in `sepolia/signatures/2026-05-13-incident-multisig-signers/`.
+
+### Task creator (run after task setup):
+```bash
+make sign-as-task-creator
+```
+
+### Base facilitator:
+```bash
+make sign-as-base-facilitator
+```
+
+### Security Council facilitator:
+```bash
+make sign-as-sc-facilitator
+```
+
+## Generate Validation File
+
+Run this after any change to [OwnerDiff.json](./OwnerDiff.json), [.env](./.env), or [script/UpdateSigners.s.sol](./script/UpdateSigners.s.sol).
+
+```bash
+cd contract-deployments
+git pull
+cd sepolia/2026-05-13-incident-multisig-signers
+make deps
+make gen-validation
+```
+
+This produces `validations/base-signer.json`. Check that the `cmd` field uses:
+
+```text
+--sender 0x644d0F5c2C55A4679b4BFe057B87ba203AF9aC0D
+```
+
+Then generate the Safe B validation:
+
+```bash
+make gen-validation-secondary
+```
+
+This produces `validations/base-signer-safe-b.json`. Check that the `cmd` field uses:
+
+```text
+OWNER_SAFE=0x6AF0674791925f767060Dd52f7fB20984E8639d8
+--sender 0x644d0F5c2C55A4679b4BFe057B87ba203AF9aC0D
+```
+
+## Collect Signatures
+
+Ask signers to follow [README.md](./README.md). They should run `make sign-task` from the repo root and select `sepolia/2026-05-13-incident-multisig-signers` in the signing UI.
+
+## Execute
+
+After collecting enough signatures:
+
+```bash
+cd contract-deployments
+git pull
+cd sepolia/2026-05-13-incident-multisig-signers
+make deps
+SIGNATURES=AAABBBCCC make execute
+```
+
+Replace `AAABBBCCC` with the concatenated signatures collected from signers.
+
+To execute the Safe B update, use:
+
+```bash
+SIGNATURES=AAABBBCCC make execute-secondary
+```
+
+After execution, update [README.md](./README.md) status to `EXECUTED` with the transaction link and check in any generated execution records.
diff --git a/sepolia/2026-05-13-incident-multisig-signers/Makefile b/sepolia/2026-05-13-incident-multisig-signers/Makefile
new file mode 100644
index 00000000..904296bc
--- /dev/null
+++ b/sepolia/2026-05-13-incident-multisig-signers/Makefile
@@ -0,0 +1,30 @@
+include ../../Makefile
+include ../../Multisig.mk
+include ../.env
+include .env
+
+RPC_URL = $(L1_RPC_URL)
+SCRIPT_NAME = UpdateSigners
+
+.PHONY: deps
+deps: new-forge-deps
+
+.PHONY: new-forge-deps
+new-forge-deps:
+	forge install --no-git safe-global/safe-smart-account@186a21a74b327f17fc41217a927dea7064f74604
+
+.PHONY: gen-validation
+gen-validation: deps-signer-tool
+	$(call GEN_VALIDATION,$(SCRIPT_NAME),,$(SENDER),base-signer.json,)
+
+.PHONY: gen-validation-secondary
+gen-validation-secondary: deps-signer-tool
+	$(call GEN_VALIDATION,$(SCRIPT_NAME),,$(SENDER),base-signer-safe-b.json,OWNER_SAFE=$(SECONDARY_SAFE))
+
+.PHONY: execute
+execute:
+	$(call MULTISIG_EXECUTE,$(SIGNATURES))
+
+.PHONY: execute-secondary
+execute-secondary:
+	OWNER_SAFE=$(SECONDARY_SAFE) $(call MULTISIG_EXECUTE,$(SIGNATURES))
diff --git a/sepolia/2026-05-13-incident-multisig-signers/OwnerDiff.json b/sepolia/2026-05-13-incident-multisig-signers/OwnerDiff.json
new file mode 100644
index 00000000..c024cd44
--- /dev/null
+++ b/sepolia/2026-05-13-incident-multisig-signers/OwnerDiff.json
@@ -0,0 +1,14 @@
+{
+  "OwnersToAdd": [
+    "0x623942f433Ee569Df78Dceac754C2ed3A3343A80",
+    "0xE167153964d4ba0819E1Ad56172F3329cD5A0263",
+    "0x98EAC95c208b74d31550fDA9dD3AD62C5d462DF9",
+    "0x821Ff2A3fB66B008fA668B40Eca9d3535B246575"
+  ],
+  "OwnersToRemove": [
+    "0x931E24B032511d8dD029AedeB44837FAc251f3d8",
+    "0xE45AC81eA7f53dea5f0bd6Caa0733DD5c02d3b60",
+    "0x7f10098BD53519c739cA8A404afE127647D94774",
+    "0xEE316Db0eDaee45347DfC498795a01311F085225"
+  ]
+}
diff --git a/sepolia/2026-05-13-incident-multisig-signers/README.md b/sepolia/2026-05-13-incident-multisig-signers/README.md
new file mode 100644
index 00000000..7ec027a7
--- /dev/null
+++ b/sepolia/2026-05-13-incident-multisig-signers/README.md
@@ -0,0 +1,61 @@
+# Update Sepolia Incident Multisig Signers
+
+Status: READY TO SIGN
+
+## Description
+
+We wish to update the owners of our [Incident Multisig](https://sepolia.etherscan.io/address/0x646132A1667ca7aD00d36616AFBA1A28116C770A) and [Safe B](https://sepolia.etherscan.io/address/0x6AF0674791925f767060Dd52f7fB20984E8639d8) on Sepolia to be consistent with the current state of our Base Chain Eng team. This involves removing signers that are no longer closely involved with the team, and adding new team members as signers. The exact signer changes are outlined in the [OwnerDiff.json](./OwnerDiff.json) file and apply to both safes.
+
+The signer changes are configured in [OwnerDiff.json](./OwnerDiff.json), and the simulation sender is configured in [.env](./.env).
+
+## Install dependencies
+
+### 1. Update foundry
+
+```bash
+foundryup
+```
+
+### 2. Install Node.js if needed
+
+First, check if you have node installed
+
+```bash
+node --version
+```
+
+If you see a version output from the above command, you can move on. Otherwise, install node
+
+```bash
+brew install node
+```
+
+## Approving Signers Update
+
+### 1. Update repo:
+
+```bash
+cd contract-deployments
+git pull
+```
+
+### 2. Run the signing tool (NOTE: do not enter the task directory. Run this command from the project's root).
+
+```bash
+make sign-task
+```
+
+### 3. Open the UI at [http://localhost:3000](http://localhost:3000)
+
+Be sure to select the correct task from the list of available tasks to sign.
+
+Task name: `sepolia/2026-05-13-incident-multisig-signers`
+
+Then select the Safe for which you would like to sign:
+
+- Incident Multisig: `validations/base-signer.json`
+- Safe B: `validations/base-signer-safe-b.json`
+
+### 4. Send signature to facilitator
+
+You may now kill the Signer Tool process in your terminal window by running `Ctrl + C`.
diff --git a/sepolia/2026-05-13-incident-multisig-signers/foundry.toml b/sepolia/2026-05-13-incident-multisig-signers/foundry.toml
new file mode 100644
index 00000000..c1d7c3e8
--- /dev/null
+++ b/sepolia/2026-05-13-incident-multisig-signers/foundry.toml
@@ -0,0 +1,19 @@
+[profile.default]
+src = 'src'
+out = 'out'
+libs = ['lib']
+broadcast = 'records'
+fs_permissions = [{ access = "read-write", path = "./" }]
+optimizer = true
+optimizer_runs = 999999
+solc_version = "0.8.15"
+via-ir = false
+evm_version = "shanghai"
+remappings = [
+    '@base-contracts/=lib/contracts/',
+]
+
+[lint]
+lint_on_build = false
+
+# See more config options https://github.com/foundry-rs/foundry/tree/master/config
diff --git a/sepolia/2026-05-13-incident-multisig-signers/script/UpdateSigners.s.sol b/sepolia/2026-05-13-incident-multisig-signers/script/UpdateSigners.s.sol
new file mode 100644
index 00000000..65b7fbb1
--- /dev/null
+++ b/sepolia/2026-05-13-incident-multisig-signers/script/UpdateSigners.s.sol
@@ -0,0 +1,131 @@
+// SPDX-License-Identifier: MIT
+pragma solidity 0.8.15;
+
+import {Vm} from "forge-std/Vm.sol";
+import {stdJson} from "forge-std/StdJson.sol";
+import {Simulation} from "@base-contracts/scripts/universal/Simulation.sol";
+
+import {MultisigScript} from "@base-contracts/scripts/universal/MultisigScript.sol";
+import {GnosisSafe} from "safe-smart-account/GnosisSafe.sol";
+import {OwnerManager} from "safe-smart-account/base/OwnerManager.sol";
+import {Enum} from "@base-contracts/scripts/universal/IGnosisSafe.sol";
+
+contract UpdateSigners is MultisigScript {
+    using stdJson for string;
+
+    address public constant SENTINEL_OWNERS = address(0x1);
+
+    address public immutable OWNER_SAFE;
+    uint256 public immutable THRESHOLD;
+    address[] public EXISTING_OWNERS;
+
+    address[] public OWNERS_TO_ADD;
+    address[] public OWNERS_TO_REMOVE;
+
+    mapping(address => address) public ownerToPrevOwner;
+    mapping(address => address) public ownerToNextOwner;
+    mapping(address => bool) public expectedOwner;
+
+    constructor() {
+        OWNER_SAFE = vm.envAddress("OWNER_SAFE");
+
+        GnosisSafe ownerSafe = GnosisSafe(payable(OWNER_SAFE));
+        THRESHOLD = ownerSafe.getThreshold();
+        EXISTING_OWNERS = ownerSafe.getOwners();
+
+        string memory rootPath = vm.projectRoot();
+        string memory path = string.concat(rootPath, "/OwnerDiff.json");
+        string memory jsonData = vm.readFile(path);
+
+        OWNERS_TO_ADD = abi.decode(jsonData.parseRaw(".OwnersToAdd"), (address[]));
+        OWNERS_TO_REMOVE = abi.decode(jsonData.parseRaw(".OwnersToRemove"), (address[]));
+    }
+
+    function setUp() external {
+        require(OWNERS_TO_ADD.length > 0, "Precheck 00");
+        require(OWNERS_TO_REMOVE.length > 0, "Precheck 01");
+
+        GnosisSafe ownerSafe = GnosisSafe(payable(OWNER_SAFE));
+        address prevOwner = SENTINEL_OWNERS;
+
+        for (uint256 i = OWNERS_TO_ADD.length; i > 0; i--) {
+            uint256 index = i - 1;
+            // Make sure owners to add are not already owners
+            require(!ownerSafe.isOwner(OWNERS_TO_ADD[index]), "Precheck 03");
+            // Prevent duplicates
+            require(!expectedOwner[OWNERS_TO_ADD[index]], "Precheck 04");
+
+            ownerToPrevOwner[OWNERS_TO_ADD[index]] = prevOwner;
+            ownerToNextOwner[prevOwner] = OWNERS_TO_ADD[index];
+            prevOwner = OWNERS_TO_ADD[index];
+            expectedOwner[OWNERS_TO_ADD[index]] = true;
+        }
+
+        for (uint256 i; i < EXISTING_OWNERS.length; i++) {
+            ownerToPrevOwner[EXISTING_OWNERS[i]] = prevOwner;
+            ownerToNextOwner[prevOwner] = EXISTING_OWNERS[i];
+            prevOwner = EXISTING_OWNERS[i];
+            expectedOwner[EXISTING_OWNERS[i]] = true;
+        }
+
+        for (uint256 i; i < OWNERS_TO_REMOVE.length; i++) {
+            // Make sure owners to remove are owners
+            require(ownerSafe.isOwner(OWNERS_TO_REMOVE[i]), "Precheck 05");
+            // Prevent duplicates
+            require(expectedOwner[OWNERS_TO_REMOVE[i]], "Precheck 06");
+            expectedOwner[OWNERS_TO_REMOVE[i]] = false;
+
+            // Remove from linked list to keep ownerToPrevOwner up to date
+            // Note: This works as long as the order of OWNERS_TO_REMOVE does not change during `_buildCalls()`
+            address nextOwner = ownerToNextOwner[OWNERS_TO_REMOVE[i]];
+            address prevPtr = ownerToPrevOwner[OWNERS_TO_REMOVE[i]];
+            ownerToPrevOwner[nextOwner] = prevPtr;
+            ownerToNextOwner[prevPtr] = nextOwner;
+        }
+    }
+
+    function _postCheck(Vm.AccountAccess[] memory, Simulation.Payload memory) internal view override {
+        GnosisSafe ownerSafe = GnosisSafe(payable(OWNER_SAFE));
+        address[] memory postCheckOwners = ownerSafe.getOwners();
+        uint256 postCheckThreshold = ownerSafe.getThreshold();
+
+        uint256 expectedLength = EXISTING_OWNERS.length + OWNERS_TO_ADD.length - OWNERS_TO_REMOVE.length;
+
+        require(postCheckThreshold == THRESHOLD, "Postcheck 00");
+        require(postCheckOwners.length == expectedLength, "Postcheck 01");
+
+        for (uint256 i; i < postCheckOwners.length; i++) {
+            require(expectedOwner[postCheckOwners[i]], "Postcheck 02");
+        }
+    }
+
+    function _buildCalls() internal view override returns (Call[] memory) {
+        Call[] memory calls = new Call[](OWNERS_TO_ADD.length + OWNERS_TO_REMOVE.length);
+
+        for (uint256 i; i < OWNERS_TO_ADD.length; i++) {
+            calls[i] = Call({
+                operation: Enum.Operation.Call,
+                target: OWNER_SAFE,
+                data: abi.encodeCall(OwnerManager.addOwnerWithThreshold, (OWNERS_TO_ADD[i], THRESHOLD)),
+                value: 0
+            });
+        }
+
+        for (uint256 i; i < OWNERS_TO_REMOVE.length; i++) {
+            calls[OWNERS_TO_ADD.length + i] = Call({
+                operation: Enum.Operation.Call,
+                target: OWNER_SAFE,
+                data: abi.encodeCall(
+                    OwnerManager.removeOwner, (ownerToPrevOwner[OWNERS_TO_REMOVE[i]], OWNERS_TO_REMOVE[i], THRESHOLD)
+                ),
+                value: 0
+            });
+        }
+
+        return calls;
+    }
+
+    function _ownerSafe() internal view override returns (address) {
+        return OWNER_SAFE;
+    }
+}
diff --git a/sepolia/2026-05-13-incident-multisig-signers/validations/base-signer-safe-b.json b/sepolia/2026-05-13-incident-multisig-signers/validations/base-signer-safe-b.json
new file mode 100644
index 00000000..247d6216
--- /dev/null
+++ b/sepolia/2026-05-13-incident-multisig-signers/validations/base-signer-safe-b.json
@@ -0,0 +1,125 @@
+{
+  "cmd": "OWNER_SAFE=0x6AF0674791925f767060Dd52f7fB20984E8639d8 forge script --rpc-url https://ethereum-full-sepolia-k8s-dev.cbhq.net UpdateSigners --sig sign(address[]) [] --sender 0x644d0F5c2C55A4679b4BFe057B87ba203AF9aC0D",
+  "ledgerId": 1,
+  "rpcUrl": "https://ethereum-full-sepolia-k8s-dev.cbhq.net",
+  "expectedDomainAndMessageHashes": {
+    "address": "0x6AF0674791925f767060Dd52f7fB20984E8639d8",
+    "domainHash": "0x6f25427e79742a1eb82c103e2bf43c85fc59509274ec258ad6ed841c4a0048aa",
+    "messageHash": "0x9ba366d3cab6734fd1c8ebd67a8c803bd7fd844806d1a5b476a637d4b85971c3"
+  },
+  "stateOverrides": [
+    {
+      "name": "Mock OP Safe / Mock Security Council - Sepolia",
+      "address": "0x6AF0674791925f767060Dd52f7fB20984E8639d8",
+      "overrides": [
+        {
+          "key": "0xfbb6102fe3ef75c822ab164e1a0b85841a7127f0b680cefeb13077ff233cb16e",
+          "value": "0x0000000000000000000000000000000000000000000000000000000000000001",
+          "description": "Simulates an approval from msg.sender in order for the task simulation to succeed.",
+          "allowDifference": false
+        }
+      ]
+    }
+  ],
+  "stateChanges": [
+    {
+      "name": "Mock OP Safe / Mock Security Council - Sepolia",
+      "address": "0x6AF0674791925f767060Dd52f7fB20984E8639d8",
+      "changes": [
+        {
+          "key": "0x0000000000000000000000000000000000000000000000000000000000000005",
+          "before": "0x0000000000000000000000000000000000000000000000000000000000000020",
+          "after": "0x0000000000000000000000000000000000000000000000000000000000000021",
+          "description": "Increments the nonce",
+          "allowDifference": false
+        },
+        {
+          "key": "0x04f5b49ecc01681da29e79068c15efdb3abde943719f9854b44138e483921ad2",
+          "before": "0x0000000000000000000000000000000000000000000000000000000000000000",
+          "after": "0x000000000000000000000000623942f433ee569df78dceac754c2ed3a3343a80",
+          "description": "Adds `0xE167153964d4ba0819E1Ad56172F3329cD5A0263` to the owners mapping and points it to `0x623942f433Ee569Df78Dceac754C2ed3A3343A80`.",
+          "allowDifference": false
+        },
+        {
+          "key": "0x1faa07ea6a4832ac192fb7e2cbd607c53ad1016be862a14dc26d02378418c601",
+          "before": "0x0000000000000000000000000000000000000000000000000000000000000000",
+          "after": "0x0000000000000000000000006e427c3212c0b63be0c382f97715d49b011bff33",
+          "description": "Adds `0x623942f433Ee569Df78Dceac754C2ed3A3343A80` to the owners mapping and points it to the previous head owner `0x6e427c3212C0b63BE0C382F97715D49b011bFF33`.",
+          "allowDifference": false
+        },
+        {
+          "key": "0x4bf34efa2cf5d17da7425df2ee4f6191d734167ae5ba396b1eaa05b9d92099f6",
+          "before": "0x000000000000000000000000420c8fe1ddb0593c71487445576c87c17f177179",
+          "after": "0x0000000000000000000000000000000000000000000000000000000000000000",
+          "description": "Removes `0xEE316Db0eDaee45347DfC498795a01311F085225` from the owners mapping.",
+          "allowDifference": false
+        },
+        {
+          "key": "0x50acbb719f16147a2c8ee75d12507825fd23cf8249e700977d21095d26e2750b",
+          "before": "0x000000000000000000000000931e24b032511d8dd029aedeb44837fac251f3d8",
+          "after": "0x000000000000000000000000edecf2c444559210a865a22acfc6a2a25590ab1b",
+          "description": "Updates `0x0CF2F86C3338993ce10F74d6f4B095712c7efe26` to skip removed owners `0x931E24B032511d8dD029AedeB44837FAc251f3d8` and `0xE45AC81eA7f53dea5f0bd6Caa0733DD5c02d3b60`, pointing it to `0xEdecf2c444559210a865a22acfc6A2a25590Ab1b`.",
+          "allowDifference": false
+        },
+        {
+          "key": "0x563d4ddf297b5a92e03dce553dc56572bfee245f134f6db63397742b674f94dd",
+          "before": "0x000000000000000000000000ee316db0edaee45347dfc498795a01311f085225",
+          "after": "0x000000000000000000000000420c8fe1ddb0593c71487445576c87c17f177179",
+          "description": "Updates `0xb2d9a52e76841279EF0372c534C539a4f68f8C0B` to skip removed owner `0xEE316Db0eDaee45347DfC498795a01311F085225`, pointing it to `0x420c8fE1dDb0593c71487445576c87c17f177179`.",
+          "allowDifference": false
+        },
+        {
+          "key": "0x789d0a937d11245f00c7805a1652391bdbf3de0209dd993a5d6bc0ea4964bd5e",
+          "before": "0x0000000000000000000000007f10098bd53519c739ca8a404afe127647d94774",
+          "after": "0x0000000000000000000000009986ccaf9e3de0ffef82a0f7fa3a06d5afe07252",
+          "description": "Updates `0xEdecf2c444559210a865a22acfc6A2a25590Ab1b` to skip removed owner `0x7f10098BD53519c739cA8A404afE127647D94774`, pointing it to `0x9986ccaf9E3DE0fFEF82a0f7fA3a06D5aFe07252`.",
+          "allowDifference": false
+        },
+        {
+          "key": "0x82f9f6d76f17715407982421d7a2ab9a5f6be8ac439648a288d69f6e86af9c2b",
+          "before": "0x0000000000000000000000000000000000000000000000000000000000000000",
+          "after": "0x000000000000000000000000e167153964d4ba0819e1ad56172f3329cd5a0263",
+          "description": "Adds `0x98EAC95c208b74d31550fDA9dD3AD62C5d462DF9` to the owners mapping and points it to `0xE167153964d4ba0819E1Ad56172F3329cD5A0263`.",
+          "allowDifference": false
+        },
+        {
+          "key": "0xb06fd2848181e1497bbaa80b8d007c335c7806a2e47211a7bba7a9af63e0ca64",
+          "before": "0x000000000000000000000000edecf2c444559210a865a22acfc6a2a25590ab1b",
+          "after": "0x0000000000000000000000000000000000000000000000000000000000000000",
+          "description": "Removes `0xE45AC81eA7f53dea5f0bd6Caa0733DD5c02d3b60` from the owners mapping.",
+          "allowDifference": false
+        },
+        {
+          "key": "0xb7148df08fba2104e13e2db097b95b457295019a50d577cc90c6010aba3100d1",
+          "before": "0x000000000000000000000000e45ac81ea7f53dea5f0bd6caa0733dd5c02d3b60",
+          "after": "0x0000000000000000000000000000000000000000000000000000000000000000",
+          "description": "Removes `0x931E24B032511d8dD029AedeB44837FAc251f3d8` from the owners mapping.",
+          "allowDifference": false
+        },
+        {
+          "key": "0xc737cf9e0b995a0b7c95319fd1b2a1daedbcafc9b244731b97e04bbf2a8067f3",
+          "before": "0x0000000000000000000000009986ccaf9e3de0ffef82a0f7fa3a06d5afe07252",
+          "after": "0x0000000000000000000000000000000000000000000000000000000000000000",
+          "description": "Removes `0x7f10098BD53519c739cA8A404afE127647D94774` from the owners mapping.",
+          "allowDifference": false
+        },
+        {
+          "key": "0xd75ac7000e645bb681b0252efd6e2374a16914e40d01873d738e67eba9190a29",
+          "before": "0x0000000000000000000000000000000000000000000000000000000000000000",
+          "after": "0x00000000000000000000000098eac95c208b74d31550fda9dd3ad62c5d462df9",
+          "description": "Adds `0x821Ff2A3fB66B008fA668B40Eca9d3535B246575` to the owners mapping and points it to `0x98EAC95c208b74d31550fDA9dD3AD62C5d462DF9`.",
+          "allowDifference": false
+        },
+        {
+          "key": "0xe90b7bceb6e7df5418fb78d8ee546e97c83a08bbccc01a0644d599ccd2a7c2e0",
+          "before": "0x0000000000000000000000006e427c3212c0b63be0c382f97715d49b011bff33",
+          "after": "0x000000000000000000000000821ff2a3fb66b008fa668b40eca9d3535b246575",
+          "description": "Sets the head of the owners linked list to newly added owner `0x821Ff2A3fB66B008fA668B40Eca9d3535B246575`.",
+          "allowDifference": false
+        }
+      ]
+    }
+  ],
+  "balanceChanges": [],
+  "skipTaskOriginValidation": true
+}
diff --git a/sepolia/2026-05-13-incident-multisig-signers/validations/base-signer.json b/sepolia/2026-05-13-incident-multisig-signers/validations/base-signer.json
new file mode 100644
index 00000000..0e7d8b2b
--- /dev/null
+++ b/sepolia/2026-05-13-incident-multisig-signers/validations/base-signer.json
@@ -0,0 +1,138 @@
+{
+  "cmd": "forge script --rpc-url https://ethereum-full-sepolia-k8s-dev.cbhq.net UpdateSigners --sig sign(address[]) [] --sender 0x644d0F5c2C55A4679b4BFe057B87ba203AF9aC0D",
+  "ledgerId": 1,
+  "rpcUrl": "https://ethereum-full-sepolia-k8s-dev.cbhq.net",
+  "skipTaskOriginValidation": true,
+  "expectedDomainAndMessageHashes": {
+    "address": "0x646132A1667ca7aD00d36616AFBA1A28116C770A",
+    "domainHash": "0x1d3f2566fd7b1bf017258b03d4d4d435d326d9cb051d5b7993d7c65e7ec78d0e",
+    "messageHash": "0xcead25b8f84d43216e51a4ad43bb1b6d002bc59799bae195b93e6c8b55cfcea9"
+  },
+  "stateOverrides": [
+    {
+      "name": "CB Coordinator Safe - Sepolia",
+      "address": "0x646132A1667ca7aD00d36616AFBA1A28116C770A",
+      "overrides": [
+        {
+          "key": "0x0000000000000000000000000000000000000000000000000000000000000004",
+          "value": "0x0000000000000000000000000000000000000000000000000000000000000001",
+          "description": "Override the threshold to 1 so the transaction simulation can occur.",
+          "allowDifference": false
+        },
+        {
+          "key": "0xdd45035935b741eae52e5412de19d5afed0cf9018bc026b246bbdcef17abee98",
+          "value": "0x0000000000000000000000000000000000000000000000000000000000000001",
+          "description": "Simulates an approval from msg.sender in order for the task simulation to succeed.",
+          "allowDifference": false
+        }
+      ]
+    }
+  ],
+  "stateChanges": [
+    {
+      "name": "CB Coordinator Safe - Sepolia",
+      "address": "0x646132A1667ca7aD00d36616AFBA1A28116C770A",
+      "changes": [
+        {
+          "key": "0x0000000000000000000000000000000000000000000000000000000000000004",
+          "before": "0x0000000000000000000000000000000000000000000000000000000000000001",
+          "after": "0x0000000000000000000000000000000000000000000000000000000000000003",
+          "description": "Sets the Safe threshold to 3, preserving the existing 3-of-13 execution threshold after the validation override.",
+          "allowDifference": false
+        },
+        {
+          "key": "0x0000000000000000000000000000000000000000000000000000000000000005",
+          "before": "0x0000000000000000000000000000000000000000000000000000000000000015",
+          "after": "0x0000000000000000000000000000000000000000000000000000000000000016",
+          "description": "Increments the nonce",
+          "allowDifference": false
+        },
+        {
+          "key": "0x04f5b49ecc01681da29e79068c15efdb3abde943719f9854b44138e483921ad2",
+          "before": "0x0000000000000000000000000000000000000000000000000000000000000000",
+          "after": "0x000000000000000000000000623942f433ee569df78dceac754c2ed3a3343a80",
+          "description": "Adds `0xE167153964d4ba0819E1Ad56172F3329cD5A0263` to the owners mapping and points it to `0x623942f433Ee569Df78Dceac754C2ed3A3343A80`.",
+          "allowDifference": false
+        },
+        {
+          "key": "0x1faa07ea6a4832ac192fb7e2cbd607c53ad1016be862a14dc26d02378418c601",
+          "before": "0x0000000000000000000000000000000000000000000000000000000000000000",
+          "after": "0x000000000000000000000000644d0f5c2c55a4679b4bfe057b87ba203af9ac0d",
+          "description": "Adds `0x623942f433Ee569Df78Dceac754C2ed3A3343A80` to the owners mapping and points it to the previous head owner `0x644d0F5c2C55A4679b4BFe057B87ba203AF9aC0D`.",
+          "allowDifference": false
+        },
+        {
+          "key": "0x4bf34efa2cf5d17da7425df2ee4f6191d734167ae5ba396b1eaa05b9d92099f6",
+          "before": "0x000000000000000000000000b2d9a52e76841279ef0372c534c539a4f68f8c0b",
+          "after": "0x0000000000000000000000000000000000000000000000000000000000000000",
+          "description": "Removes `0xEE316Db0eDaee45347DfC498795a01311F085225` from the owners mapping.",
+          "allowDifference": false
+        },
+        {
+          "key": "0x789d0a937d11245f00c7805a1652391bdbf3de0209dd993a5d6bc0ea4964bd5e",
+          "before": "0x000000000000000000000000e45ac81ea7f53dea5f0bd6caa0733dd5c02d3b60",
+          "after": "0x0000000000000000000000000cf2f86c3338993ce10f74d6f4b095712c7efe26",
+          "description": "Updates `0xEdecf2C444559210a865a22aCFc6A2a25590Ab1b` to skip removed owners `0xE45AC81eA7f53dea5f0bd6Caa0733DD5c02d3b60` and `0x931E24B032511d8dD029AedeB44837FAc251f3d8`, pointing it to `0x0CF2F86C3338993ce10F74d6f4B095712c7efe26`.",
+          "allowDifference": false
+        },
+        {
+          "key": "0x7a83097f5b56a04accdbc8d4b0501bec3106db0d2c2ea1a63e7cbbf0fa91372d",
+          "before": "0x0000000000000000000000007f10098bd53519c739ca8a404afe127647d94774",
+          "after": "0x000000000000000000000000edecf2c444559210a865a22acfc6a2a25590ab1b",
+          "description": "Updates `0x9986ccaf9E3DE0fFEF82a0f7fA3a06D5aFe07252` to skip removed owner `0x7f10098BD53519c739cA8A404afE127647D94774`, pointing it to `0xEdecf2C444559210a865a22aCFc6A2a25590Ab1b`.",
+          "allowDifference": false
+        },
+        {
+          "key": "0x82f9f6d76f17715407982421d7a2ab9a5f6be8ac439648a288d69f6e86af9c2b",
+          "before": "0x0000000000000000000000000000000000000000000000000000000000000000",
+          "after": "0x000000000000000000000000e167153964d4ba0819e1ad56172f3329cd5a0263",
+          "description": "Adds `0x98EAC95c208b74d31550fDA9dD3AD62C5d462DF9` to the owners mapping and points it to `0xE167153964d4ba0819E1Ad56172F3329cD5A0263`.",
+          "allowDifference": false
+        },
+        {
+          "key": "0xb06fd2848181e1497bbaa80b8d007c335c7806a2e47211a7bba7a9af63e0ca64",
+          "before": "0x000000000000000000000000931e24b032511d8dd029aedeb44837fac251f3d8",
+          "after": "0x0000000000000000000000000000000000000000000000000000000000000000",
+          "description": "Removes `0xE45AC81eA7f53dea5f0bd6Caa0733DD5c02d3b60` from the owners mapping.",
+          "allowDifference": false
+        },
+        {
+          "key": "0xb7148df08fba2104e13e2db097b95b457295019a50d577cc90c6010aba3100d1",
+          "before": "0x0000000000000000000000000cf2f86c3338993ce10f74d6f4b095712c7efe26",
+          "after": "0x0000000000000000000000000000000000000000000000000000000000000000",
+          "description": "Removes `0x931E24B032511d8dD029AedeB44837FAc251f3d8` from the owners mapping.",
+          "allowDifference": false
+        },
+        {
+          "key": "0xc737cf9e0b995a0b7c95319fd1b2a1daedbcafc9b244731b97e04bbf2a8067f3",
+          "before": "0x000000000000000000000000edecf2c444559210a865a22acfc6a2a25590ab1b",
+          "after": "0x0000000000000000000000000000000000000000000000000000000000000000",
+          "description": "Removes `0x7f10098BD53519c739cA8A404afE127647D94774` from the owners mapping.",
+          "allowDifference": false
+        },
+        {
+          "key": "0xd75ac7000e645bb681b0252efd6e2374a16914e40d01873d738e67eba9190a29",
+          "before": "0x0000000000000000000000000000000000000000000000000000000000000000",
+          "after": "0x00000000000000000000000098eac95c208b74d31550fda9dd3ad62c5d462df9",
+          "description": "Adds `0x821Ff2A3fB66B008fA668B40Eca9d3535B246575` to the owners mapping and points it to `0x98EAC95c208b74d31550fDA9dD3AD62C5d462DF9`.",
+          "allowDifference": false
+        },
+        {
+          "key": "0xdd723b4c2a66aea3d2ac26f837bd1e7dea4ce6cca7e4fa76af2185076784453f",
+          "before": "0x000000000000000000000000ee316db0edaee45347dfc498795a01311f085225",
+          "after": "0x000000000000000000000000b2d9a52e76841279ef0372c534c539a4f68f8c0b",
+          "description": "Updates `0x420c8fE1dDb0593c71487445576c87c17f177179` to skip removed owner `0xEE316Db0eDaee45347DfC498795a01311F085225`, pointing it to `0xb2d9a52e76841279EF0372c534C539a4f68f8C0B`.",
+          "allowDifference": false
+        },
+        {
+          "key": "0xe90b7bceb6e7df5418fb78d8ee546e97c83a08bbccc01a0644d599ccd2a7c2e0",
+          "before": "0x000000000000000000000000644d0f5c2c55a4679b4bfe057b87ba203af9ac0d",
+          "after": "0x000000000000000000000000821ff2a3fb66b008fa668b40eca9d3535b246575",
+          "description": "Sets the head of the owners linked list to newly added owner `0x821Ff2A3fB66B008fA668B40Eca9d3535B246575`.",
+          "allowDifference": false
+        }
+      ]
+    }
+  ],
+  "balanceChanges": []
+}