What’s Vulnerable › Vulnerabilities

CVE-2021-31551

• Severity: medium (CVSS 6.1 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.9% 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 PageForms extension for MediaWiki through 1.35.2. Crafted payloads for Token-related query parameters allowed for XSS on certain PageForms-managed MediaWiki pages.

Affected products

• Wikimedia Foundation MediaWiki: through 1.35.2

References

• https://gerrit.wikimedia.org/r/q/I20b63bd38779d2ccbe2d86f9879df85ca3b685f6
• https://gerrit.wikimedia.org/r/q/I5e0abbc2f80e6bda255b3b32a4df39a7fe7d3793
• https://gerrit.wikimedia.org/r/q/Ibe68b070ee791cd0c8e7f50eb04ac4e066b1512c
• https://phabricator.wikimedia.org/T259433
• https://gerrit.wikimedia.org/r/q/I20b63bd38779d2ccbe2d86f9879df85ca3b685f6
• https://gerrit.wikimedia.org/r/q/I5e0abbc2f80e6bda255b3b32a4df39a7fe7d3793
• https://gerrit.wikimedia.org/r/q/Ibe68b070ee791cd0c8e7f50eb04ac4e066b1512c
• https://phabricator.wikimedia.org/T259433

Get alerted when CVE-2021-31551 or the next vulnerability affects your stack