What is CVE-2026-37977?

CVE-2026-37977 is a low-severity vulnerability in Red Hat Build Of Keycloak, classified under Origin Validation Error. CVSS score: 3.7/10. Published 2026-04-06.

How severe is CVE-2026-37977?

Low severity. CVSS v3 base score is 3.7 out of 10.

Vulnerability in Red Hat Build Of Keycloak

CVE-2026-37977

A flaw was found in Keycloak. A remote attacker can exploit a Cross-Origin Resource Sharing (CORS) header injection vulnerability in Keycloak's User-Managed Access (UMA) token endpoint. This flaw occurs because the `azp` claim from a clien…

EPSS: 0.000 (0.9th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 3.7 (Low). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N.

Affected products

Red Hat Build Of Keycloak

Weakness classification (CWE)

CWE-346 — Origin Validation Error

References

access.redhat.com/security/cve/CVE-2026-37977 (vdb-entry, x_refsource_REDHAT)
RHBZ#2455324 (issue-tracking, x_refsource_REDHAT)

Frequently asked questions

What is CVE-2026-37977?: CVE-2026-37977 is a low-severity vulnerability in Red Hat Build Of Keycloak, classified under Origin Validation Error. CVSS score: 3.7/10. Published 2026-04-06.
How severe is CVE-2026-37977?: Low severity. CVSS v3 base score is 3.7 out of 10.