PT-2026-55159

A flaw was found in Keycloak. An authenticated user with low privileges can exploit this vulnerability by sending an oversized subject token JSON Web Token JWT to the TokenEndpoint. When the token exceeds a 4000-character limit, it is silently dropped, causing the system to fall back to client...

PT-2026-43993

Name of the Vulnerable Software and Affected Versions Keycloak affected versions not specified Description An authenticated user with low privileges can achieve privilege escalation by sending an oversized JSON Web Token JWT, which is a compact, URL-safe means of representing claims to be...

PT-2026-43682

Name of the Vulnerable Software and Affected Versions Keycloak affected versions not specified Description A flaw in Keycloak, an open-source identity and access management solution, allows a remote attacker to manipulate the authentication process by crafting a special web address. This occurs...

The vulnerability of the SAML Endpoint component of the Keycloak identity and access management software allows a attacker to trigger a service denial.

The vulnerability of the SAML Endpoint component of the Keycloak identity and access management software lies in improper syntax validation during input verification. Exploiting this vulnerability could allow an attacker to trigger a service failure...

PT-2026-55165

A flaw was found in Keycloak, an open-source identity and access management solution. When a client application is configured to accept broad redirect Uniform Resource Identifiers URIs, a remote attacker can manipulate the authentication process by crafting a special web address. If a user clicks...

CVE-2026-9689: Improper Validation of Consistency within Input

A flaw was found in Keycloak, an open-source identity and access management solution. When a client application is configured to accept broad redirect Uniform Resource Identifiers URIs, a remote attacker can manipulate the authentication process by crafting a special web address. If a user clicks...

Keycloak: Insufficient verification proof scoping enables identity provider account linking attack and account compromise

A flaw was found in Keycloak. The cross-session verification proof is keyed only by local userId, idpAlias and is not bound to the upstream identity that was actually verified, so a second upstream account on the same IdP can consume it and get linked to the victim's local account...

GHSA-M6QJ-3MPP-57V8 Keycloak: Insufficient verification proof scoping enables identity provider account linking attack and account compromise

A flaw was found in Keycloak. The cross-session verification proof is keyed only by local userId, idpAlias and is not bound to the upstream identity that was actually verified, so a second upstream account on the same IdP can consume it and get linked to the victim's local account...

CVE-2026-9087

A flaw was found in Keycloak. The cross-session verification proof is keyed only by local userId, idpAlias and is not bound to the upstream identity that was actually verified, so a second upstream account on the same IdP can consume it and get linked to the victim's local account...

CVE-2026-9087

A flaw was found in Keycloak. The cross-session verification proof is keyed only by local userId, idpAlias and is not bound to the upstream identity that was actually verified, so a second upstream account on the same IdP can consume it and get linked to the victim's local account...

EUVD-2026-31134

A flaw was found in Keycloak. The cross-session verification proof is keyed only by local userId, idpAlias and is not bound to the upstream identity that was actually verified, so a second upstream account on the same IdP can consume it and get linked to the victim's local account...

CVE-2026-9087 Keycloak: cross-session email verification proof not bound to upstream identity in first-broker-login

A flaw was found in Keycloak. The cross-session verification proof is keyed only by local userId, idpAlias and is not bound to the upstream identity that was actually verified, so a second upstream account on the same IdP can consume it and get linked to the victim's local account...

CVE-2026-9087

CVE-2026-9087 : In Keycloak, the cross-session verification proof is keyed only by (local userId, idpAlias) and is not bound to the upstream identity actually verified, allowing a second upstream account on the same IdP to be linked to the victim’s local account. Affected component: Keycloak auth...

CVE-2026-9087

A flaw was found in Keycloak. The cross-session verification proof is keyed only by local userId, idpAlias and is not bound to the upstream identity that was actually verified, so a second upstream account on the same IdP can consume it and get linked to the victim's local account. Mitigation To...

Authorization Bypass Through User-Controlled Key

Overview org.keycloak:keycloak-services is an open source identity and access management solution for modern applications and services. Affected versions of this package are vulnerable to Authorization Bypass Through User-Controlled Key in the cross-session email verification process. An attacker...

Important: Red Hat Security Advisory: Red Hat build of Keycloak 26.4.12 Images Security Update

New images are available for Red Hat build of Keycloak 26.4.12 and Red Hat build of Keycloak 26.4.12 Operator, running on OpenShift Container Platform Red Hat build of Keycloak is an integrated sign-on solution, available as a Red Hat JBoss Middleware for OpenShift containerized image. The Red Ha...

Important: Red Hat Security Advisory: Red Hat build of Keycloak 26.2.16 Security Update

New Red Hat build of Keycloak 26.2.16 packages are available from the Customer Portal Red Hat build of Keycloak 26.2.16 is a standalone server, based on the Keycloak project, that provides authentication and standards-based single sign-on capabilities for web and mobile applications. Security...

org.keycloak/keycloak-services: Open redirect when using wildcard valid redirect URIs in Keycloak

A flaw was found in Keycloak's URL validation logic during redirect operations. By crafting a malicious request, an attacker could bypass validation to redirect users to unauthorized URLs, potentially leading to the exposure of sensitive information within the domain or facilitating further...

keycloak: Keycloak: Denial of Service via specially crafted SAML input

A flaw was found in Keycloak. A remote, unauthenticated attacker can send a specially crafted XML input to the Security Assertion Markup Language SAML endpoint. This malicious input can cause high CPU usage and worker thread starvation, leading to a Denial of Service DoS where the server becomes...

org.keycloak/keycloak-services: Session fixation in OIDC login flow that can lead to account takeover

A session fixation vulnerability was found in Keycloak's login-actions endpoints. An unauthenticated attacker could exploit this flaw by pre-creating an authentication session and tricking a victim into visiting a maliciously crafted link. By leveraging the /login-actions/restart endpoint—which...