CVE-2026-103046 WikifunctionsFragmentRenderer does unsafe string replacements on user-provided HTML
Stored XSS in MediaWiki WikiLambda extension allows attackers to inject malicious scripts via unsafe HTML string replacements.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2026-103046?
CVE-2026-103046 is a medium-severity cross-site scripting vulnerability in The Wikimedia Foundation Mediawiki - WikiLambda Extension, published on 29 Sep 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official description
Improper neutralization of input during web page generation ('cross-site scripting') vulnerability in Wikimedia Foundation MediaWiki - WikiLambda extension allows Stored XSS.
This issue affects MediaWiki - WikiLambda extension: before 1.46.1.
Weakness: CWE-79
Which versions are affected by CVE-2026-103046?
How do I fix CVE-2026-103046?
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-2026-103046 being exploited?
There is no known exploitation of CVE-2026-103046 in the wild and no public exploit code.
Sources
Also known as GHSA-wgjv-5xcv-4jq5, MINI-9895-mpmw-mw8v.