CVE-2026-58037 Core log entries for exceptions and XSS issues in log entry formatting code that may be caused by user-controlled input
An attacker can inject malicious scripts via user-controlled input in log entries, potentially leading to code execution or data theft in MediaWiki installations.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2026-58037?
CVE-2026-58037 is a cross-site scripting vulnerability in Mediawiki Mediawiki, published on 1 Jul 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Official description
Improper Neutralization of Input During Web Page Generation (XSS or 'Cross-site Scripting') vulnerability in Wikimedia Foundation MediaWiki.
This vulnerability is associated with program files includes/Language/Language.Php, includes/Logging/BlockLogFormatter.Php, includes/Logging/LogFormatter.Php, includes/Logging/PatrolLogFormatter.Php, includes/Logging/RenameuserLogFormatter.Php, includes/Logging/TagLogFormatter.Php, includes/Specials/SpecialVersion.Php.
This issue affects MediaWiki: from * before 1.46.0, 1.45.4, 1.44.6, 1.43.9.
Weakness: CWE-79
Which versions are affected by CVE-2026-58037?
It affects 1 product.
Products include Mediawiki Mediawiki.
How do I fix CVE-2026-58037?
Upgrade to a fixed version.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2026-58037 being exploited?
There is no known exploitation of CVE-2026-58037 in the wild and no public exploit code.
Other vulnerabilities in Mediawiki Mediawiki
Sources
Also known as DEBIAN-CVE-2026-58037, GHSA-c9c4-xmc2-5h6x, MINI-9q2c-cq73-2xc4, MINI-fmgr-g2hr-gw7w, MINI-pvhq-q572-3735, UBUNTU-CVE-2026-58037.