CVE-2015-8623: Mediawiki

High severity, CVSS 8.8. EPSS: 0.7% chance of exploitation in the next 30 days.

The User::matchEditToken function in includes/User.php in MediaWiki before 1.23.12 and 1.24.x before 1.24.5 does not perform token comparison in constant time before returning, which allows remote attackers to guess the edit token and bypass CSRF protection via a timing attack, a different vulnerability than CVE-2015-8624.

Affected products

• Mediawiki Mediawiki: up to and including 1.23.11; version 1.24.0 only; version 1.24.1 only; version 1.24.2 only; version 1.24.3 only; version 1.24.4 only

Published 2017-03-23. Last modified 2026-06-17.