CVE-2026-34087: Users API leaks whether privileged users have their user groups disabled for lack of 2FA
Published May 11, 2026
·Updated
Exposure of Sensitive Information to an Unauthorized Actor vulnerability in Wikimedia Foundation OATHAuth.
Affected Software
5 affected componentsFixes available
Wikimedia Foundation OATHAuth<1.43.7, =1.44.4, =1.45.2
MediaWiki MediaWiki<1.43.7
MediaWiki MediaWiki>=1.44.0<1.44.4
MediaWiki MediaWiki>=1.45.0<1.45.2
debian/mediawiki<=1:1.35.13-1+deb11u2, <=1:1.35.13-1+deb11u6
1:1.39.17-1+deb12u21:1.43.8+dfsg-1~deb13u11:1.43.8+dfsg-2
Event History
May 11, 2026
CVE Published
via MITRE·02:40 PM
Data Sourced
via MITRE·02:40 PM
DescriptionWeakness
Data Sourced
via NVD·04:17 PM
DescriptionSeverityWeaknessAffected Software
May 27, 2026
Data Sourced
via Ubuntu·02:12 PM
RemedyDescriptionSeverityAffected Software
Data Sourced
via Launchpad·02:12 PM
Description
Data Sourced
via Debian·02:13 PM
DescriptionAffected Software
Frequently Asked Questions
1
What is the severity of CVE-2026-34087?
CVE-2026-34087 has a medium severity level due to the potential exposure of sensitive information.
2
How do I fix CVE-2026-34087?
To fix CVE-2026-34087, upgrade Wikimedia Foundation OATHAuth to version 1.43.7 or later, and ensure that your MediaWiki installation is updated past version 1.45.2.
3
What is the impact of CVE-2026-34087?
CVE-2026-34087 allows unauthorized users to determine whether privileged users have their user groups disabled due to a lack of two-factor authentication.
4
Which versions are affected by CVE-2026-34087?
CVE-2026-34087 affects Wikimedia Foundation OATHAuth versions prior to 1.43.7, 1.44.4, and 1.45.2.
5
Who is impacted by CVE-2026-34087?
Users of Wikimedia Foundation OATHAuth and MediaWiki versions specified in CVE-2026-34087 are at risk.