CVE-2026-56668
ZITADEL is an open source identity management platform. Prior to 4.15.3, ZITADEL's OAuth2 Token Exchange endpoint for urn:ietf:params:oauth:grant-type:token-exchange does not verify that the subject token belongs to the requesting client or that requested scopes remain within the original token's scopes, allowing a low-privilege token to be exchanged for elevated permissions at another application. This issue is fixed in version 4.15.3.
No public exploitation has been reported so far. No distribution fix is listed yet; apply vendor mitigations and monitor.
Recommended action: Track your distribution's security tracker and apply the fix as soon as it ships.
Severity metrics
CVSS 3.1 : 8.1 HIGH
Vector: AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
Affected & fixed versions by distribution
Versions are the native distribution strings (backport-aware): RHEL/Debian/SUSE backport fixes, so compare with the distro version comparator (dpkg / rpm / vercmp), not the upstream version.
No affected package in the tracked watchlist yet (Debian, Ubuntu, Arch, SUSE, Red Hat...). Triage may still be pending.