CVE-2026-37979
Keycloak: keycloak: information disclosure via oidc token introspection endpoint audience bypass
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.
INFO
Published Date :
May 19, 2026, 12:16 p.m.
Last Modified :
Oct. 29, 2026, 10:17 a.m.
Remotely Exploit :
Yes !
Source :
[email protected]
Affected Products
The following products are affected by CVE-2026-37979
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | MEDIUM | 53f830b8-0a3f-465b-8143-3b8a9948e749 | ||||
| CVSS 3.1 | MEDIUM | [email protected] | ||||
| CVSS 3.1 | MEDIUM | MITRE-CVE |
Solution
- Update Keycloak to the latest version.
- Apply vendor-provided security patches.
- Restrict access to the introspection endpoint.
Public PoC/Exploit Available at Github
CVE-2026-37979 has a 1 public
PoC/Exploit available at Github.
Go to the Public Exploits tab to see the list.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-37979.
| URL | Resource |
|---|---|
| https://access.redhat.com/errata/RHSA-2026:19596 | Vendor Advisory |
| https://access.redhat.com/errata/RHSA-2026:19597 | Vendor Advisory |
| https://access.redhat.com/security/cve/CVE-2026-37979 | Vendor Advisory |
| https://bugzilla.redhat.com/show_bug.cgi?id=2455328 | Vendor Advisory |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-37979 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-37979
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
None
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-37979 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-37979 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Modified by [email protected]
Oct. 29, 2026
Action Type Old Value New Value Added CWE CWE-639 Added Reference https://access.redhat.com/errata/RHSA-2026:19596 Added Reference https://access.redhat.com/errata/RHSA-2026:19597 Added Reference https://access.redhat.com/security/cve/CVE-2026-37979 Added Reference https://bugzilla.redhat.com/show_bug.cgi?id=2455328 Removed Reference https://access.redhat.com/errata/RHSA-2026:19596 Removed Reference https://access.redhat.com/errata/RHSA-2026:19597 Removed Reference https://access.redhat.com/security/cve/CVE-2026-37979 Removed Reference https://bugzilla.redhat.com/show_bug.cgi?id=2455328 Removed Reference Type https://access.redhat.com/errata/RHSA-2026:19596 Types: Vendor Advisory Removed Reference Type https://access.redhat.com/errata/RHSA-2026:19597 Types: Vendor Advisory Removed Reference Type https://access.redhat.com/security/cve/CVE-2026-37979 Types: Vendor Advisory Removed Reference Type https://bugzilla.redhat.com/show_bug.cgi?id=2455328 Types: Vendor Advisory -
CVE Translated by [email protected]
Oct. 26, 2026
Action Type Old Value New Value Added Translation Title: Linux Kernel, Description: Se encontró una falla en Keycloak. Esta vulnerabilidad de control de acceso en el endpoint de introspección de tokens de OpenID Connect (OIDC) de Keycloak permite a un cliente confidencial eludir las restricciones de audiencia. Un cliente controlado por un atacante con credenciales válidas puede recuperar claims de token sensibles destinados a otros servidores de recursos, comprometiendo la confidencialidad de los tokens de acceso ligeros. Este problema puede ser explotado remotamente por cualquier cliente confidencial en el realm con credenciales válidas. -
CVE Modified by [email protected]
Jun. 17, 2026
Action Type Old Value New Value Added Affected [{'cpes': ['cpe:/a:redhat:build_keycloak:26.4::el9'], 'vendor': 'Red Hat', 'product': 'Red Hat build of Keycloak 26.4', 'versions': [{'status': 'unaffected', 'version': '26.4.12-1', 'lessThan': '*', 'versionType': 'rpm'}], 'packageName': 'rhbk/keycloak-operator-bundle', 'collectionURL': 'https://catalog.redhat.com/software/containers/', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:build_keycloak:26.4::el9'], 'vendor': 'Red Hat', 'product': 'Red Hat build of Keycloak 26.4', 'versions': [{'status': 'unaffected', 'version': '26.4-17', 'lessThan': '*', 'versionType': 'rpm'}], 'packageName': 'rhbk/keycloak-rhel9', 'collectionURL': 'https://catalog.redhat.com/software/containers/', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:build_keycloak:26.4::el9'], 'vendor': 'Red Hat', 'product': 'Red Hat build of Keycloak 26.4', 'versions': [{'status': 'unaffected', 'version': '26.4-17', 'lessThan': '*', 'versionType': 'rpm'}], 'packageName': 'rhbk/keycloak-rhel9-operator', 'collectionURL': 'https://catalog.redhat.com/software/containers/', 'defaultStatus': 'affected'}, {'cpes': ['cpe:/a:redhat:build_keycloak:26.4::el9'], 'vendor': 'Red Hat', 'product': 'Red Hat build of Keycloak 26.4.12', 'packageName': 'rhbk/keycloak-rhel9', 'collectionURL': 'https://access.redhat.com/downloads/content/package-browser/', 'defaultStatus': 'unaffected'}] -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Jun. 17, 2026
Action Type Old Value New Value Added SSVC {'id': 'CVE-2026-37979', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-05-19T13:39:36.285295Z'} -
Initial Analysis by [email protected]
Jun. 03, 2026
Action Type Old Value New Value Added CPE Configuration OR *cpe:2.3:a:redhat:build_of_keycloak:*:*:*:*:*:*:*:* versions from (including) 26.4 up to (excluding) 26.4.12 Added Reference Type Red Hat, Inc.: https://access.redhat.com/errata/RHSA-2026:19596 Types: Vendor Advisory Added Reference Type Red Hat, Inc.: https://access.redhat.com/errata/RHSA-2026:19597 Types: Vendor Advisory Added Reference Type Red Hat, Inc.: https://access.redhat.com/security/cve/CVE-2026-37979 Types: Vendor Advisory Added Reference Type Red Hat, Inc.: https://bugzilla.redhat.com/show_bug.cgi?id=2455328 Types: Vendor Advisory -
CVE Modified by [email protected]
May. 20, 2026
Action Type Old Value New Value Added Reference https://access.redhat.com/errata/RHSA-2026:19596 -
CVE Modified by [email protected]
May. 20, 2026
Action Type Old Value New Value Added Reference https://access.redhat.com/errata/RHSA-2026:19597 -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
May. 19, 2026
Action Type Old Value New Value Added CWE CWE-284 -
New CVE Received by [email protected]
May. 19, 2026
Action Type Old Value New Value Added 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. Added CVSS V3.1 AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N Added Reference https://access.redhat.com/security/cve/CVE-2026-37979 Added Reference https://bugzilla.redhat.com/show_bug.cgi?id=2455328