CVE-2026-96872: WikiLambda public function execution bypasses the unsaved-code permission through nested Z825 compositions

Severity: low (CVSS 2.9 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: 2026-09-23 · updated 2026-09-24
Weakness: CWE-280

Description

Improper handling of insufficient permissions or privileges vulnerability in The Wikimedia Foundation Mediawiki - WikiLambda Extension on Linux, MacOS, and Windows allows Accessing Functionality Not Properly Constrained by ACLs. This issue affects Mediawiki - WikiLambda Extension: before 1.47.0.

Affected products

Wikimedia Foundation MediaWiki: before 1.47.0 — fixed in 1.47.0

How to fix

Upgrade to a fixed version: Wikimedia Foundation MediaWiki 1.47.0. Check the vendor advisory for mitigations.

References

https://gerrit.wikimedia.org/r/c/mediawiki/extensions/WikiLambda/+/1326392
https://phabricator.wikimedia.org/T435085

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