CVE-2025-61650Public exploitNetwork attack vector

Stored XSS via unescaped group messages

Published Feb 3, 2026 · Updated Feb 3, 2026

Stored XSS in Wikimedia Foundation CheckUser before 795bf333272206a0189050d975e94b70eb7dc507 allows remote authenticated users to run script. CheckUserUserInfoCardService renders overridden group-* and user-info-card group messages into the User Info card without HTML escaping. High-privilege access is required to store a malicious interface-message override, and script runs when another user opens the affected card, exposing that user's browser data.

CVSS severityUnavailable
Unscored
EPSS probability0.26%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Stored XSS in Wikimedia Foundation CheckUser before 795bf333272206a0189050d975e94b70eb7dc507 allows remote authenticated users to run script. CheckUserUserInfoCardService renders overridden group-* and user-info-card group messages into the User Info card without HTML escaping. High-privilege access is required to store a malicious interface-message override, and script runs when another user opens the affected card, exposing that user's browser data.

The record

CVE
CVE-2025-61650
Published
Feb 3, 2026
Updated
Feb 3, 2026
Vendor
Wikimedia Foundation
Product
CheckUser
Classifications
CWE-79, T1059.007
Attack vector
network
Privileges
admin

Timeline

How it unfolded

  1. Feb 3, 2026CVE publishedPublication date reported by the CVE source.
  2. Feb 3, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=* <795bf333272206a0189050d975e94b70eb7dc507

What conditions does exploitation require?

Attack vectornetwork
Required privilegesadmin

What is affected?

Wikimedia Foundation · CheckUserversion=* <795bf333272206a0189050d975e94b70eb7dc507

Published CVSS scores

1.1Wikimedia FoundationCVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:U

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesadmin
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1059.007JavaScript/JScript

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo