CVE-2025-61637 Stored XSS through system messages in MW Core
Attackers can inject malicious scripts via system messages in MediaWiki, potentially leading to session hijacking or code execution.
- Exploited in the wild
- Not known
- Login needed
- An administrator
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2025-61637?
CVE-2025-61637 is a cross-site scripting vulnerability in Mediawiki Mediawiki, published on 2 Feb 2026. An attacker needs administrator access to exploit it, with no action from the victim.
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 resources/src/mediawiki.Action/mediawiki.Action.Edit.Preview.Js, resources/src/mediawiki.Page.Preview.Js.
This issue affects MediaWiki: from * before 1.39.14, 1.43.4, 1.44.1.
Weakness: CWE-79
Which versions are affected by CVE-2025-61637?
It affects 1 product.
Products include Mediawiki Mediawiki.
How do I fix CVE-2025-61637?
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-2025-61637 being exploited?
There is no known exploitation of CVE-2025-61637 in the wild and no public exploit code.
Other vulnerabilities in Mediawiki Mediawiki
Sources
Also known as DEBIAN-CVE-2025-61637, GHSA-j3hj-c3rr-4j34, UBUNTU-CVE-2025-61637.