CVE-2026-37979

Name: CVE-2026-37979
Creator: NVD / NIST
Published: 2026-05-19T12:16:18.33+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 6.5/10EPSS 0.37%

Last modified Jun 17, 2026

CVE-2026-37979 is a medium-severity vulnerability rated 6.5/10 on the CVSS scale. 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. EPSS estimates a 0.37% chance of exploitation in the next 30 days.

Description

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.

Metrics

CVSS 3.1

6.5/10

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

EPSS Probability

0.37%

28.4th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-284

Affected Software

Vendor	Product	Versions
Redhat	Build Of Keycloak	>= 26.4, < 26.4.12

References

https://access.redhat.com/errata/RHSA-2026:19596Vendor Advisory
https://access.redhat.com/errata/RHSA-2026:19597Vendor Advisory
https://access.redhat.com/security/cve/CVE-2026-37979Vendor Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=2455328Vendor Advisory

Timeline

Published: May 19, 2026
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2026-37979?

How severe is CVE-2026-37979?

CVE-2026-37979 has a CVSS score of 6.5/10 (MEDIUM severity). The EPSS model estimates a 0.37% probability of exploitation in the next 30 days.

How do I fix CVE-2026-37979?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2026-37979?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST