CVE-2026-37979

What it is

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.

At a glance

Exploitability

Can be exploited over the network with a low-privilege account. High risk of data exposure.

Exploit odds

0.4% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2026-05-19 12:16 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-10-29 10:17 UTC Last updatedMost recent change to the record

Details

Published

2026-05-19 12:16 UTC

Last modified

2026-10-29 10:17 UTC

Exploit probability

0.4% · EPSS, next 30 days

Weakness

CWE-639 · Insecure direct object reference

Record status

Modified

Affected

• Redhat Build Of Keycloak < 26.4.12

Attack profile CVSS 3.1 · 6.5

Attack vector

Network

Complexity

Low

Privileges needed

Low

User interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

None

Availability

None