CVE-2026-42998

Name	CVE-2026-42998
Description	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.
Source	CVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)
References	DLA-4611-1, DSA-6331-1

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
keystone (PTS)	bullseye	2:18.0.0-3+deb11u1	vulnerable
	bullseye (security)	2:18.1.0-1+deb11u3	fixed
	bookworm	2:22.0.2-0+deb12u1	vulnerable
	bookworm (security)	2:22.0.2-0+deb12u3	fixed
	trixie	2:27.0.0-3+deb13u1	vulnerable
	trixie (security)	2:27.0.0-3+deb13u4	fixed
	forky, sid	2:29.0.1-2	fixed

The information below is based on the following data on fixed versions.

Package	Type	Release	Fixed Version	Origin
keystone	source	bullseye	2:18.1.0-1+deb11u3	DLA-4611-1
keystone	source	bookworm	2:22.0.2-0+deb12u3	DSA-6331-1
keystone	source	trixie	2:27.0.0-3+deb13u4	DSA-6331-1
keystone	source	(unstable)	2:29.0.1-2

https://bugs.launchpad.net/keystone/+bug/2148477
https://security.openstack.org/ossa/OSSA-2026-015.html