CVE-2026-103446 WikiLambda exposes anonymous execution of unsaved Abstract Wikipedia fragments
Attackers can bypass authentication to access unsaved Abstract Wikipedia fragments in the WikiLambda extension, exposing sensitive draft data.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-103446?
CVE-2026-103446 is a high-severity missing authorization vulnerability in The Wikimedia Foundation MediaWiki WikiLambda extension, published on 30 Sep 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Official description
Authorization bypass through User-Controlled key vulnerability in The Wikimedia Foundation MediaWiki WikiLambda extension allows Authentication Bypass.
This issue affects MediaWiki WikiLambda extension: 1.46.
Weakness: CWE-639
Which versions are affected by CVE-2026-103446?
How do I fix CVE-2026-103446?
No fix has been published for CVE-2026-103446 yet. Limit exposure of the affected software until one is available.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2026-103446 being exploited?
There is no known exploitation of CVE-2026-103446 in the wild and no public exploit code.
Public exploit code: 1 proofs of concept on GitHub.
Sources
Also known as GHSA-4x94-p99h-wrcj.