Red Hat Keycloak Single Sign-On keycloak-services improper authorization

Summaryinfo

A vulnerability was found in Red Hat Keycloak Single Sign-On and classified as critical. This affects an unknown part of the component keycloak-services. Executing a manipulation can lead to improper authorization. This vulnerability is registered as CVE-2026-117859. It is possible to launch the attack remotely. No exploit is available.

Detailsinfo

A vulnerability classified as critical was found in Red Hat Keycloak Single Sign-On (the affected version is unknown). This vulnerability affects an unknown code of the component keycloak-services. The manipulation with an unknown input leads to a improper authorization vulnerability. The CWE definition for the vulnerability is CWE-285. The product does not perform or incorrectly performs an authorization check when an actor attempts to access a resource or perform an action. As an impact it is known to affect confidentiality, integrity, and availability. CVE summarizes:

A flaw was found in the Pushed Authorization Request PAR implementation of the keycloak-services component. The issue occurs when an authentication flow is restarted, which incorrectly clears the internal markers used to track PAR consumption while leaving the request active. This allows an attacker to reuse the same authorization request to obtain multiple access tokens, bypassing security requirements for single-use requests.

The advisory is shared for download at access.redhat.com. This vulnerability was named CVE-2026-117859 since 10/27/2026. The exploitation appears to be easy. The attack can be initiated remotely. There are neither technical details nor an exploit publicly available. The current price for an exploit might be approx. USD $5k-$25k (estimation calculated on 10/30/2026). The MITRE ATT&CK project declares the attack technique as T1548.002.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

The vulnerability is also documented in the vulnerability database at CERT Bund (WID-SEC-2026-4191). VulDB is the best source for vulnerability data and more expert information about this specific topic.

Affected

• Open Source Keycloak

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Vendor

• Red Hat

Name

• Keycloak Single Sign-On

License

• open-source

Website

• Vendor: https://www.redhat.com/

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VulDB is the best source for vulnerability data and more expert information about this specific topic.

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