CVE-2026-34091

HIGH

Wikimedia Foundation MediaWiki - User Localization Leaked by AbuseFilter + EventStream

Title source: rule

Description

Exposure of Sensitive Information to an Unauthorized Actor vulnerability in Wikimedia Foundation MediaWiki. This issue affects MediaWiki: from * before 1.43.7, 1.44.4, 1.45.2.

References (1)

Core 1

Core References

https://phabricator.wikimedia.org/T411305

Scores

CVSS v3 7.5

EPSS 0.0004

EPSS Percentile 12.2%

Attack Vector NETWORK

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

CISA SSVC

Vulnrichment

Exploitation none

Automatable yes

Technical Impact partial

Details

CWE

CWE-200

Status published

Products (2)

mediawiki/mediawiki < 1.43.7

Wikimedia Foundation/MediaWiki < 1.43.7, 1.44.4, 1.45.2

Published May 11, 2026

Tracked Since May 11, 2026