Skip to content

Conversation

@renovate
Copy link
Contributor

@renovate renovate bot commented Aug 19, 2025

This PR contains the following updates:

Package Change Age Confidence
mermaid 11.9.0 -> 11.10.0 age confidence

GitHub Vulnerability Alerts

CVE-2025-54880

Summary

In the default configuration of mermaid 11.9.0, user supplied input for architecture diagram icons is passed to the d3 html() method, creating a sink for cross site scripting.

Details

Architecture diagram service iconText values are passed to the d3 html() method, allowing malicious users to inject arbitrary HTML and cause XSS when mermaid-js is used in it's default configuration.

The vulnerability lies here:

export const drawServices = async function (
  db: ArchitectureDB,
  elem: D3Element,
  services: ArchitectureService[]
): Promise<number> {
  for (const service of services) {
    /** ... **/
    } else if (service.iconText) {
      bkgElem.html(
        `<g>${await getIconSVG('blank', { height: iconSize, width: iconSize, fallbackPrefix: architectureIcons.prefix })}</g>`
      );
      const textElemContainer = bkgElem.append('g');
      const fo = textElemContainer
        .append('foreignObject')
        .attr('width', iconSize)
        .attr('height', iconSize);
      const divElem = fo
        .append('div')
        .attr('class', 'node-icon-text')
        .attr('style', `height: ${iconSize}px;`)
        .append('div')
        .html(service.iconText); // <- iconText passed into innerHTML
       /** ... **/
};
};

This issue was introduced with 734bde38777c9190a5a72e96421c83424442d4e4, around 15 months ago, which was released in v11.1.0.

PoC

Render the following diagram and observe the modified DOM.

architecture-beta
    group api(cloud)[API]
    service db "<img src=x onerror=\"document.write(`xss on ${document.domain}`)\">" [Database] in api

Here is a PoC on mermaid.live: https://mermaid.live/edit#pako:eNo9T8FOwzAM_ZXI4rBJpWrpRtuIISF24caZZdKyxOsiLUnlJjCo-u9kQ8wX-_n5-dkjKK8ROEhSRxNQhUh4v8cghWMpOvKxZ7I3M3XyUc83L-9v2z9qQPo0CpneMwFPxnZsILU6M--QyNNKCAHaq2jRhfyL0vLZ7jwMiWd3443Q3krjpt38Mv4sgG3WMsi9HHDLjLs4CwcZdGQ08EARM7BISZMgjJdLBIQjWhTAU6nxIOMpCBBuSrJeug_v7b8yPdMdgR_kaUgo9loGXBvZkbS3LqHTSK8-ugC8LMrrEuAjnIEvlnlVL9q6rZu6Lh-rRQbfwKuyyZuybcvqIaWiqKcMfq6uRd7Uy-kXhYFzcA

Impact

XSS on all sites that use mermaid and render user supplied diagrams without further sanitization.

Remediation

Sanitize the value of iconText before passing it to html().

CVE-2025-54881

Summary

In the default configuration of mermaid 11.9.0, user supplied input for sequence diagram labels is passed to innerHTML during calculation of element size, causing XSS.

Details

Sequence diagram node labels with KaTeX delimiters are passed through calculateMathMLDimensions. This method passes the full label to innerHTML which allows allows malicious users to inject arbitrary HTML and cause XSS when mermaid-js is used in it's default configuration (with KaTeX support enabled).

The vulnerability lies here:

export const calculateMathMLDimensions = async (text: string, config: MermaidConfig) => {
  text = await renderKatex(text, config);
  const divElem = document.createElement('div');
  divElem.innerHTML = text; // XSS sink, text has not been sanitized.
  divElem.id = 'katex-temp';
  divElem.style.visibility = 'hidden';
  divElem.style.position = 'absolute';
  divElem.style.top = '0';
  const body = document.querySelector('body');
  body?.insertAdjacentElement('beforeend', divElem);
  const dim = { width: divElem.clientWidth, height: divElem.clientHeight };
  divElem.remove();
  return dim;
};

The calculateMathMLDimensions method was introduced in 5c69e5fdb004a6d0a2abe97e23d26e223a059832 two years ago, which was released in Mermaid 10.9.0.

PoC

Render the following diagram and observe the modified DOM.

sequenceDiagram
    participant A as Alice<img src="x" onerror="document.write(`xss on ${document.domain}`)">$$\\text{Alice}$$
    A->>John: Hello John, how are you?
    Alice-)John: See you later!

Here is a PoC on mermaid.live: https://mermaid.live/edit#pako:eNpVUMtOwzAQ_BWzyoFKaRTyaFILiio4IK7ckA-1km1iKbaLY6spUf4dJ0AF68uOZ2dm7REqXSNQ6PHDoarwWfDGcMkUudaJGysqceLKkj3hPdl3osJ7IRvSm-qBwcCAaIXGaONRrSsnUdnobITF28PQ954lwXglai25UNNhxWAXBMyXxcGOi-3kL_5k79e73atuFSUv2HWazH1IWn0m3CC5aPf4b3p2WK--BW-4DJCOWzQ3TM0HQmiMqIFa4zAEicZv4iGMsw0D26JEBtS3NR656ywDpiYv869_11r-Ko12TQv0yLveI3eqfcjP111HUNVonrRTFuhdsVgAHWEAmuRxlG7SuEzKMi-yJAnhAjTLIk_EcbFJtuk2y9MphM8lM47KIp--AOZghtU

Impact

XSS on all sites that use mermaid and render user supplied diagrams without further sanitization.

Remediation

The value of the text argument for the calculateMathMLDimensions method needs to be sanitized before getting passed on to innerHTML.


Release Notes

mermaid-js/mermaid (mermaid)

v11.10.0

Compare Source

Minor Changes
Patch Changes

Configuration

📅 Schedule: Branch creation - "" (UTC), Automerge - At any time (no schedule defined).

🚦 Automerge: Disabled by config. Please merge this manually once you are satisfied.

Rebasing: Whenever PR becomes conflicted, or you tick the rebase/retry checkbox.

🔕 Ignore: Close this PR and you won't be reminded about this update again.


  • If you want to rebase/retry this PR, check this box

This PR was generated by Mend Renovate. View the repository job log.

@netlify
Copy link

netlify bot commented Aug 19, 2025

Deploy Preview for elastic-elion-a958b6 ready!

Name Link
🔨 Latest commit 540613a
🔍 Latest deploy log https://app.netlify.com/projects/elastic-elion-a958b6/deploys/6930887196de4d0008d02b6f
😎 Deploy Preview https://deploy-preview-377--elastic-elion-a958b6.netlify.app
📱 Preview on mobile
Toggle QR Code...

QR Code

Use your smartphone camera to open QR code link.

To edit notification comments on pull requests, go to your Netlify project configuration.

@renovate renovate bot force-pushed the renovate/npm-mermaid-vulnerability branch from 0f58bc6 to e5a95d7 Compare August 31, 2025 14:32
@renovate renovate bot changed the title fix(deps): update dependency mermaid to v11.10.0 [security] Update dependency mermaid to v11.10.0 [SECURITY] Sep 9, 2025
@renovate renovate bot changed the title Update dependency mermaid to v11.10.0 [SECURITY] fix(deps): update dependency mermaid to v11.10.0 [security] Sep 10, 2025
@renovate renovate bot changed the title fix(deps): update dependency mermaid to v11.10.0 [security] Update dependency mermaid to v11.10.0 [SECURITY] Sep 19, 2025
@renovate renovate bot force-pushed the renovate/npm-mermaid-vulnerability branch from e5a95d7 to 0e70e26 Compare September 25, 2025 18:31
@renovate renovate bot changed the title Update dependency mermaid to v11.10.0 [SECURITY] chore(deps): update dependency mermaid to v11.10.0 [security] Sep 26, 2025
@renovate renovate bot force-pushed the renovate/npm-mermaid-vulnerability branch from 0e70e26 to 8c66020 Compare October 21, 2025 11:54
@renovate renovate bot changed the title chore(deps): update dependency mermaid to v11.10.0 [security] Update dependency mermaid to v11.10.0 [SECURITY] Oct 21, 2025
@renovate renovate bot force-pushed the renovate/npm-mermaid-vulnerability branch from 8c66020 to 982d6a3 Compare November 10, 2025 15:16
@renovate renovate bot changed the title Update dependency mermaid to v11.10.0 [SECURITY] chore(deps): update dependency mermaid to v11.10.0 [security] Nov 12, 2025
@renovate renovate bot force-pushed the renovate/npm-mermaid-vulnerability branch from 982d6a3 to 6f512d4 Compare November 18, 2025 14:47
@renovate renovate bot force-pushed the renovate/npm-mermaid-vulnerability branch from 6f512d4 to 540613a Compare December 3, 2025 18:58
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment

Labels

None yet

Projects

None yet

Development

Successfully merging this pull request may close these issues.

1 participant