Red Hat Keycloak/Single Sign-On Kerberos Federation Provider improper authorization

Summaryinfo

A vulnerability, which was classified as critical, has been found in Red Hat Keycloak and Single Sign-On. The affected element is an unknown function of the component Kerberos Federation Provider. Performing a manipulation results in improper authorization. This vulnerability is identified as CVE-2026-95503. The attack can be initiated remotely. There is not any exploit available.

Detailsinfo

A vulnerability was found in Red Hat Keycloak and Single Sign-On (affected version unknown). It has been classified as critical. This affects an unknown functionality of the component Kerberos Federation Provider. The manipulation with an unknown input leads to a improper authorization vulnerability. CWE is classifying the issue as 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. This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE is:

A flaw was found in the Kerberos federation provider of Keycloak, an open-source identity and access management solution. When Kerberos password authentication is used without SPNEGO, the system fails to verify the identity of the Key Distribution Center (KDC) by requesting a server ticket. This allows an attacker on the same network to spoof the KDC and bypass the authentication process, potentially gaining unauthorized access to user accounts.

The advisory is shared at access.redhat.com. This vulnerability is uniquely identified as CVE-2026-95503 since 09/22/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. Neither technical details nor an exploit are publicly available. The price for an exploit might be around USD $5k-$25k at the moment (estimation calculated on 09/22/2026). MITRE ATT&CK project uses the attack technique T1548.002 for this issue.

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

If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Productinfo

Vendor

• Red Hat

Name

• Keycloak
• Single Sign-On

License

• open-source

Website

• Vendor: https://www.redhat.com/

CPE 2.3info

• 🔒
• 🔒

CPE 2.2info

• 🔒
• 🔒

CVSSv4info

CVSSv3info

CVSSv2info

Exploitinginfo

Threat Intelligenceinfo

Countermeasuresinfo

Timelineinfo

Sourcesinfo

Entryinfo

If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Discussion