CVE-2025-62670 Stored XSS through a system message in FlexDiagrams
Attackers can inject malicious scripts via system messages in the FlexDiagrams extension, potentially compromising user sessions.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2025-62670?
CVE-2025-62670 is a medium-severity cross-site scripting vulnerability in The Wikimedia Foundation Mediawiki - FlexDiagrams Extension, published on 18 Oct 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
Improper Neutralization of Input During Web Page Generation (XSS or 'Cross-site Scripting') vulnerability in The Wikimedia Foundation Mediawiki - FlexDiagrams Extension allows Stored XSS.This issue affects Mediawiki - FlexDiagrams Extension: master.
Weakness: CWE-79
Which versions are affected by CVE-2025-62670?
How do I fix CVE-2025-62670?
No fix has been published for CVE-2025-62670 yet. Limit exposure of the affected software until one is available.
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-2025-62670 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-62670 exists.
Sources
Also known as GHSA-9qj7-x8cr-xhx2.