Vulnerability in MediaWiki Checkuser

CVE-2025-67478

Vulnerability in Wikimedia Foundation CheckUser. This vulnerability is associated with program files includes/Mail/UserMailer.Php. This issue affects CheckUser: from * before 1.39.14, 1.43.4, 1.44.1.

Published · last modified .

CVSS v3 metric

CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.004 (29.1th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 29th percentile — 29.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2025-67478: held from 0.003 to 0.004.

EPSS over last 30 days · oldest: 0.003 · newest: 0.004 · change: +0.000

Affected products

References

Frequently asked questions

What is CVE-2025-67478?
CVE-2025-67478 is a high-severity vulnerability in MediaWiki Checkuser. CVSS score: 8.8/10. Published 2026-02-03.
How severe is CVE-2025-67478?
High severity. CVSS v3 base score is 8.8 out of 10.