How severe is CVE-2025-61651?

CVE-2025-61651 has a CVSS 3.x base score of 6.1, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.

Is CVE-2025-61651 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (8th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2025-61651?

CVE-2025-61651 affects Mediawiki Checkuser. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2025-61651?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2025-61651 have an EU (EUVD) identifier?

Yes. CVE-2025-61651 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-206637.

When was CVE-2025-61651 published?

CVE-2025-61651 was published on 2026-02-03 and last updated on 2026-06-17.

CVE-2025-61651

CVE-2025-61651 is a medium-severity vulnerability in Mediawiki Checkuser with a CVSS 3.x base score of 6.1. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-79.

Key facts

Severity: Medium (CVSS 3.x base score 6.1)
CVSS v4: 0.0
EPSS exploit prediction: 0% (8th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2025-206637
Weakness: CWE-79
Affected product: Mediawiki Checkuser
Published: 2026-02-03
Last modified: 2026-06-17

Description

Improper Neutralization of Input During Web Page Generation (XSS or 'Cross-site Scripting') vulnerability in Wikimedia Foundation CheckUser. This vulnerability is associated with program files modules/ext.CheckUser/checkuser/checkUserHelper/buildUserElement.Js. This issue affects CheckUser: from * before 1.44.1.

Frequently asked questions

What is CVE-2025-61651?: Improper Neutralization of Input During Web Page Generation (XSS or 'Cross-site Scripting') vulnerability in Wikimedia Foundation CheckUser. This vulnerability is associated with program files modules/ext.CheckUser/checkuser/checkUserHelper/buildUserElement.Js. This issue affects CheckUser: from * before 1.44.1.
How severe is CVE-2025-61651?: CVE-2025-61651 has a CVSS 3.x base score of 6.1, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.
Is CVE-2025-61651 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (8th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2025-61651?: CVE-2025-61651 affects Mediawiki Checkuser. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2025-61651?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2025-61651 have an EU (EUVD) identifier?: Yes. CVE-2025-61651 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-206637.
When was CVE-2025-61651 published?: CVE-2025-61651 was published on 2026-02-03 and last updated on 2026-06-17.

References

https://phabricator.wikimedia.org/T403408

Affected products (1)

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

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