How severe is CVE-2025-67478?

CVE-2025-67478 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2025-67478 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (22nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2025-67478?

CVE-2025-67478 primarily affects Mediawiki Checkuser. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2025-67478?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

Does CVE-2025-67478 have an EU (EUVD) identifier?

Yes. CVE-2025-67478 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-206755.

When was CVE-2025-67478 published?

CVE-2025-67478 was published on 2026-02-03 and last updated on 2026-06-17.

CVE-2025-67478

CVE-2025-67478 is a high-severity vulnerability in Mediawiki Checkuser with a CVSS 3.x base score of 8.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.

Key facts

Severity: High (CVSS 3.x base score 8.8)
CVSS v4: 0.0
EPSS exploit prediction: 0% (22nd percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2025-206755
Affected product: Mediawiki Checkuser
Published: 2026-02-03
Last modified: 2026-06-17

Description

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.

Frequently asked questions

What is 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.
How severe is CVE-2025-67478?: CVE-2025-67478 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2025-67478 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (22nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2025-67478?: CVE-2025-67478 primarily affects Mediawiki Checkuser. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2025-67478?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2025-67478 have an EU (EUVD) identifier?: Yes. CVE-2025-67478 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-206755.
When was CVE-2025-67478 published?: CVE-2025-67478 was published on 2026-02-03 and last updated on 2026-06-17.

References

https://phabricator.wikimedia.org/T385403

Affected products (2)

cpe:2.3:a:mediawiki:checkuser:*:*:*:*:*:mediawiki:*:*
cpe:2.3:a:mediawiki:checkuser:1.44.0:*:*:*:*:mediawiki:*:*

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