Redhat: >> Build Of Keycloak Security Vulnerabilities
A flaw was found in Keycloak. This authentication vulnerability allows a remote attacker to replay `ExecuteActionsActionToken` tokens within Keycloak's WebAuthn (Web Authentication) flow. By intercepting an execute-actions email link, an attacker can register their own authenticator to a victim's account. This leads to unauthorized enrollment of a hardware-backed credential, enabling persistent account takeover.
CVSS Score
6.8
EPSS Score
0.0
Published
2026-05-19
A flaw was found in Keycloak. A low-privilege administrator with the 'view-clients' role can exploit this by invoking the 'evaluate-scopes' Admin API endpoints with an arbitrary user ID (userId) parameter. This vulnerability allows for cross-role personally identifiable information (PII) leakage, enabling unauthorized visibility into user identities and authorizations across the realm. Exploitation is possible remotely via network access to the Admin API.
CVSS Score
4.9
EPSS Score
0.0
Published
2026-05-19
A flaw was found in Keycloak. When both realm-level and client-level `notBefore` revocation policies are configured, Keycloak's OpenID Connect (OIDC) Introspection feature fails to properly honor the realm-level policy. This allows tokens that should have been revoked to remain active, potentially leading to unauthorized access or continued session validity. This could impact the security of systems utilizing Keycloak for identity and access management.
CVSS Score
5.4
EPSS Score
0.0
Published
2026-05-19
A flaw was found in Keycloak. An authenticated user can bypass configured WebAuthn policies during credential registration by manipulating client-side JavaScript. This occurs because the server-side processAction() fails to validate that the newly created credential's parameters, such as public key algorithms, match the realm's configured WebAuthn policies. This could lead to the creation of credentials that do not adhere to administrative security requirements, potentially weakening the overall security posture of the system by allowing non-compliant authentication methods.
CVSS Score
4.3
EPSS Score
0.0
Published
2026-05-19
When Keycloak is started with `--features-disabled=account,account-api`, the Account REST API is only partially disabled. Five endpoints under the versioned path `/account/v1alpha1` remain fully functional — including both read and write operations — because they lack the `checkAccountApiEnabled()` gate that correctly blocks four other endpoints in the same REST service class. The user needs to have permissions to use the API.
CVSS Score
5.4
EPSS Score
0.0
Published
2026-04-30
A flaw was found in Keycloak, specifically in the organization selection login page. A remote attacker with `manage-realm` or `manage-organizations` administrative privileges can exploit a Stored Cross-Site Scripting (XSS) vulnerability. This flaw occurs because the `organization.alias` is placed into an inline JavaScript `onclick` handler, allowing a crafted JavaScript payload to execute in a user's browser when they view the login page. Successful exploitation enables arbitrary JavaScript execution, potentially leading to session theft, unauthorized account actions, or further attacks against users of the affected realm.
CVSS Score
6.9
EPSS Score
0.0
Published
2026-04-14
A flaw was found in Keycloak. A remote attacker can exploit a Cross-Origin Resource Sharing (CORS) header injection vulnerability in Keycloak's User-Managed Access (UMA) token endpoint. This flaw occurs because the `azp` claim from a client-supplied JSON Web Token (JWT) is used to set the `Access-Control-Allow-Origin` header before the JWT signature is validated. When a specially crafted JWT with an attacker-controlled `azp` value is processed, this value is reflected as the CORS origin, even if the grant is later rejected. This can lead to the exposure of low-sensitivity information from authorization server error responses, weakening origin isolation, but only when a target client is misconfigured with `webOrigins: ["*"]`.
CVSS Score
3.7
EPSS Score
0.0
Published
2026-04-06
A flaw was found in Keycloak. An unauthenticated attacker can exploit this vulnerability by sending a specially crafted POST request with an excessively long scope parameter to the OpenID Connect (OIDC) token endpoint. This leads to high resource consumption and prolonged processing times, ultimately resulting in a Denial of Service (DoS) for the Keycloak server.
CVSS Score
7.5
EPSS Score
0.0
Published
2026-04-02
A flaw was found in Keycloak. An authenticated user with the uma_protection role can bypass User-Managed Access (UMA) policy validation. This allows the attacker to include resource identifiers owned by other users in a policy creation request, even if the URL path specifies an attacker-owned resource. Consequently, the attacker gains unauthorized permissions to victim-owned resources, enabling them to obtain a Requesting Party Token (RPT) and access sensitive information or perform unauthorized actions.
CVSS Score
8.1
EPSS Score
0.0
Published
2026-04-02
A flaw was found in Keycloak. This issue allows an attacker, who controls another path on the same web server, to bypass the allowed path in redirect Uniform Resource Identifiers (URIs) that use a wildcard. A successful attack may lead to the theft of an access token, resulting in information disclosure.
CVSS Score
7.3
EPSS Score
0.0
Published
2026-04-02