An issue was discovered in OpenStack Keystone before 29.0.2. POST /v3/credentials did not validate that the caller-supplied project_id for an EC2-type credential matched the project of the authenticating application credential. This allowed an attacker holding an unrestricted application credential for project A to create an EC2 credential targeting project B; a subsequent /v3/ec2tokens exchange would then issue a Keystone token scoped to project B while still carrying the original app_cred_id, enabling cross-project lateral movement within the credential owner's role footprint.
https://security.openstack.org/ossa/OSSA-2026-015.html
https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-43001.json
https://review.opendev.org/c/openstack/keystone/+/985804
https://bugzilla.redhat.com/show_bug.cgi?id=2464305