CVE-2021-38155: Openstack Keystone

High severity, CVSS 7.5. EPSS: 2.5% chance of exploitation in the next 30 days.

OpenStack Keystone 10.x through 16.x before 16.0.2, 17.x before 17.0.1, 18.x before 18.0.1, and 19.x before 19.0.1 allows information disclosure during account locking (related to PCI DSS features). By guessing the name of an account and failing to authenticate multiple times, any unauthenticated actor could both confirm the account exists and obtain that account's corresponding UUID, which might be leveraged for other unrelated attacks. All deployments enabling security_compliance.lockout_failure_attempts are affected.

Affected products

• Openstack Keystone: from 10.0.0, before 16.0.2 (fixed in 16.0.2); from 17.0.0, before 17.0.1 (fixed in 17.0.1); from 18.0.0, before 18.0.1 (fixed in 18.0.1); from 19.0.0, before 19.0.1 (fixed in 19.0.1)

Published 2021-08-06. Last modified 2026-06-17.