What’s Vulnerable › Vulnerabilities

CVE-2021-31550

• Severity: medium (CVSS 5.4 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.4% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2021-04-22 · updated 2026-06-17
• Weakness: CWE-79

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.

Affected products

• Wikimedia Foundation MediaWiki: through 1.35.2

References

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

Get alerted when CVE-2021-31550 or the next vulnerability affects your stack