CVE-2025-62693: Stored XSS through system messages in LastModified

Severity: medium (CVSS 6.9 v4.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-10-20 · updated 2026-10-08
Weakness: CWE-79

Description

Improper Neutralization of Input During Web Page Generation (XSS or 'Cross-site Scripting') vulnerability in The Wikimedia Foundation Mediawiki - LastModified Extension allows Stored XSS.This issue affects Mediawiki - LastModified Extension: from master before 1.39.

Affected products

The Wikimedia Foundation Mediawiki - LastModified Extension: from master before 1.39 — fixed in 1.39

How to fix

Upgrade to a fixed version: The Wikimedia Foundation Mediawiki - LastModified Extension 1.39. Check the vendor advisory for mitigations.

References

https://gerrit.wikimedia.org/r/q/Ia406630dbac5ef9a9aed3f402f0ba6e434a6bcf2
https://phabricator.wikimedia.org/T399583

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