Red Hat Keycloak Client Policies data authenticity

Summaryinfo

A vulnerability classified as problematic has been found in Red Hat Keycloak. Affected by this issue is some unknown functionality of the component Client Policies. Performing a manipulation results in data authenticity. This vulnerability is known as CVE-2026-16093. Remote exploitation of the attack is possible. No exploit is available.

Detailsinfo

A vulnerability, which was classified as problematic, was found in Red Hat Keycloak (version now known). This affects some unknown processing of the component Client Policies. The manipulation with an unknown input leads to a data authenticity vulnerability. CWE is classifying the issue as CWE-345. The product does not sufficiently verify the origin or authenticity of data, in a way that causes it to accept invalid data. This is going to have an impact on confidentiality. The summary by CVE is:

Keycloak provides a mechanism called Client Policies to enforce security requirements on clients, such as requiring them to use signed JWTs for authentication. A flaw was discovered where this enforcement can be bypassed. An attacker with valid client credentials can provide a fake, unsigned assertion header that tricks the system into thinking the policy requirements have been met. This allows the attacker to authenticate using simpler methods like a client secret even when the administrator has mandated more secure, signed assertions.

It is possible to read the advisory at access.redhat.com. This vulnerability is uniquely identified as CVE-2026-16093 since 07/17/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. The technical details are unknown and an exploit is not publicly available. The pricing for an exploit might be around USD $5k-$25k at the moment (estimation calculated on 07/17/2026).

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

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Productinfo

Vendor

• Red Hat

Name

• Keycloak

License

• open-source

Website

• Vendor: https://www.redhat.com/

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