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.

There are packages installed that are affected by a vulnerability referenced in the following CVE:

  - 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. (CVE-2026-37979)

Keycloak versions installed prior to 26.6.2 are affected by multiple vulnerabilities, including:

  - A flaw was found in Keycloak's redirect URI validation logic. An attacker can bypass     validation to redirect users to malicious sites, potentially leading to phishing attacks and     credential theft. (CVE-2026-7504)

  - A session fixation vulnerability exists in the OIDC login flow. An unauthenticated attacker     can pre-create sessions leading to account takeover if a user logs in using the attacker's     session. (CVE-2026-7507)

  - A flaw was found in Keycloak's SAML endpoint processing. A crafted XML request to the SAML     endpoint can cause a denial of service by consuming excessive server resources. (CVE-2026-7307)

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

ID	Name	Product	Family	Type	Severity
459309	Echo: keycloak-25: security update to 25.0.6+e1org.keycloak:keycloak-services: security update to 26.6.2	Tenable Cloud Security	Echo Local Security Checks	Local	medium
459309	Echo: keycloak-25: security update to 25.0.6+e1org.keycloak:keycloak-services: security update to 26.6.2	Tenable Self-Hosted Container Security	Echo Local Security Checks	Local	medium
442648	SCA: security update for org.keycloak:keycloak-services (GHSA-4x37-hw65-52w8)	Tenable Cloud Security	SCA Checks	Local	medium
442648	SCA: security update for org.keycloak:keycloak-services (GHSA-4x37-hw65-52w8)	Tenable Self-Hosted Container Security	SCA Checks	Local	medium
316461	Keycloak < 26.6.2 Multiple Vulnerabilities	Nessus	Misc.	Local	medium

Detections

Analytics

CVE-2026-37979

medium

Tenable Plugins

medium

medium

medium

medium

medium