CVE-2025-62665: Stored XSS through system messages in Skin:BlueSky

Severity: medium (CVSS 6.9 v4.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.4% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-10-18 · updated 2026-10-09
Weakness: CWE-79

Description

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

Affected products

Wikimedia Foundation Mediawiki - Skin:BlueSky: from master before 1.39 — fixed in 1.39

How to fix

Upgrade to a fixed version: Wikimedia Foundation Mediawiki - Skin:BlueSky 1.39. Check the vendor advisory for mitigations.

References

https://gerrit.wikimedia.org/r/q/I64c9e2983ed6629505f72ef9449c09137b3c69ae
https://phabricator.wikimedia.org/T401046

Get alerted when CVE-2025-62665 or the next vulnerability affects your stack