CVE-2026-58027 Wikimedia Foundation CVE debrief

Who should care

Administrators and users of MediaWiki AbuseFilter versions before 1.46.0, 1.45.4, 1.44.6, and 1.43.9 should apply patches to prevent exposure of sensitive information. This includes reviewing the official advisory for guidance on patching and mitigation, and verifying the affected versions of AbuseFilter.

Technical summary

The Exposure of Sensitive Information to an Unauthorized Actor vulnerability in Wikimedia Foundation AbuseFilter affects versions before 1.46.0, 1.45.4, 1.44.6, and 1.43.9. This issue is associated with program files includes/Api/QueryAbuseFilters.Php. The vulnerability has a CVSS score of 5.3 and a severity of MEDIUM. To prevent exposure of sensitive information, administrators and users of affected versions should apply patches.

Defensive priority

Apply patches to vulnerable versions of AbuseFilter to prevent exposure of sensitive information. Review the official advisory for guidance on patching and mitigation, and verify the affected versions of AbuseFilter.

Recommended defensive actions

• Apply patches to vulnerable versions of AbuseFilter
• Inventory and update affected versions of AbuseFilter
• Monitor for potential exploitation attempts
• Review compensating controls for exposed systems while remediation is scheduled and verified
• Check relevant monitoring, detection, and logs for exposed assets that need extra review
• Track exceptions, retest remediated assets, and close the item only after evidence is documented
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up

Evidence notes

The CVE record and NVD entry provide details on the vulnerability and affected versions. However, further information on the vulnerability's impact and exploitation is limited. Defenders should verify the affected versions of AbuseFilter and review the official advisory for guidance on patching and mitigation. The Exposure of Sensitive Information to an Unauthorized Actor vulnerability in Wikimedia Foundation AbuseFilter affects versions before 1.46.0, 1.45.4, 1.44.6, and 1.43.9. This issue is associated with program files includes/Api/QueryAbuseFilters.Php.

Official resources