Sensitive Information Exposure in Wikimedia CheckUser
CVE-2026-34090

4.8MEDIUM

Key Information:

Vendor

Wikimedia Foundation

Status
Checkuser
Vendor
CVE Published:
11 May 2026

What is CVE-2026-34090?

A vulnerability in the Wikimedia Foundation's CheckUser tool allows unauthorized actors to access sensitive information. This affects CheckUser versions from 1.45.0 and prior to 1.45.2, posing risks to user privacy and data security.

Affected Version(s)

CheckUser 1.45.0 < 1.45.2

References

https://phabricator.wikimedia.org/T411366

CVSS V4

Score:
4.8
Severity:
MEDIUM
Confidentiality:
Low
Integrity:
None
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
Unknown

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.