Vulnerability in Keycloak
CVE-2026-90997
A flaw was found in Keycloak. When deployed in stateless mode with MySQL or MariaDB, a mismatch in row-count semantics between the database driver and Keycloak's application logic allows an attacker to bypass replay protection. This vulnerability enables an attacker who intercepts single-use security artifacts, such as JWT client assertions, DPoP proofs, or one-time password (TOTP) codes, to replay them. Successful exploitation grants unauthorized access to the token endpoint or login flow.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.4 (High). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N.
EPSS exploit prediction
EPSS: 0.004 (33.9th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 34th percentile — 33.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: 0.000
Affected products
Weakness classification (CWE)
References
- access.redhat.com/security/cve/cve-2026-90997 (vdb-entry)
- github.com/keycloak/keycloak (product)
- access.redhat.com/security/cve/CVE-2026-90997 (vdb-entry)
- bugzilla.redhat.com/show_bug.cgi (issue-tracking)
Frequently asked questions
- What is CVE-2026-90997?
- CVE-2026-90997 is a high-severity vulnerability in Keycloak, classified under Authentication Bypass by Capture-replay. CVSS score: 7.4/10. Published 2026-09-17.
- How severe is CVE-2026-90997?
- High severity. CVSS v3 base score is 7.4 out of 10.