CVE-2021-44856: 
NixOS vulnerability analysis and mitigation

An issue was discovered in MediaWiki before 1.35.5, 1.36.x before 1.36.3, and 1.37.x before 1.37.1. A title blocked by AbuseFilter can be created via Special:ChangeContentModel due to the mishandling of the EditFilterMergedContent hook return value (CVE Details).

The vulnerability affects multiple versions of MediaWiki including versions before 1.35.5, 1.36.x before 1.36.3, and 1.37.x before 1.37.1. The issue specifically involves the mishandling of the EditFilterMergedContent hook return value in the Special:ChangeContentModel functionality, which could bypass AbuseFilter restrictions (Debian Security).

The vulnerability allows attackers to bypass AbuseFilter restrictions and create titles that should be blocked. This could potentially lead to unauthorized content creation and bypass of established content filtering mechanisms (Gentoo Security).

Users are advised to upgrade to MediaWiki version 1.35.5 or later, 1.36.3 or later, or 1.37.1 or later, depending on their installation branch. Package managers have also released updates: Gentoo users should upgrade to mediawiki-1.38.5 or later (Gentoo Security).