CVE-2026-42998: Openstack Keystone

High severity, CVSS 8.8. EPSS: 0.4% chance of exploitation in the next 30 days.

An issue was discovered in OpenStack Keystone before 29.0.2. The Keystone application credential authentication plugin does not verify that the user supplied in the authentication request matches the owner of the application credential. An attacker can authenticate with their own application credential ID and secret while specifying a different user's name and domain in the request body. Keystone issues a token attributed to the victim user. The impersonated token is project-scoped and carries the intersection of the application credential's roles and the victim's actual roles on the project. This enables audit evasion, reading the victim's credentials, and acting as the victim within shared projects.

Affected products

• Openstack Keystone: from 14.0.0, before 27.0.2 (fixed in 27.0.2); from 28.0.0, before 28.0.2 (fixed in 28.0.2); from 29.0.0, before 29.0.2 (fixed in 29.0.2)

Published 2026-05-28. Last modified 2026-06-17.