Vulnerability in Red Hat Build Of Keycloak
CVE-2026-37979
A flaw was found in Keycloak. This access control vulnerability in Keycloak's OpenID Connect (OIDC) token introspection endpoint allows a confidential client to bypass audience restrictions. An attacker-controlled client with valid credentials can retrieve sensitive token claims intended for other resource servers, compromising the confidentiality of lightweight access tokens. This issue can be exploited remotely by any confidential client in the realm with valid credentials.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N.
EPSS exploit prediction
EPSS: 0.004 (33.2th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 33rd percentile — 33.2% 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
- Red Hat Build Of Keycloak
- Red Hat Build Of Keycloak 26.4 — versions 26.4.12-1, 26.4-17
- Red Hat Build Of Keycloak
Weakness classification (CWE)
References
- access.redhat.com/security/cve/CVE-2026-37979 (vdb-entry, Vendor Advisory)
- bugzilla.redhat.com/show_bug.cgi (issue-tracking, Vendor Advisory)
- access.redhat.com/errata/RHSA-2026:19597 (vendor-advisory, Vendor Advisory)
- access.redhat.com/errata/RHSA-2026:19596 (vendor-advisory, Vendor Advisory)
Frequently asked questions
- What is CVE-2026-37979?
- CVE-2026-37979 is a medium-severity vulnerability in Red Hat Build Of Keycloak, classified under Improper Access Control. CVSS score: 6.5/10. Published 2026-05-19.
- How severe is CVE-2026-37979?
- Medium severity. CVSS v3 base score is 6.5 out of 10.