CVE-2026-74909 Red Hat CVE debrief

Who should care

Defenders responsible for Keycloak configurations and user access controls should assess exposure and prioritize patching to prevent unauthorized access. This includes reviewing and updating Keycloak configurations, monitoring for suspicious activity on Keycloak-protected applications, and verifying patches have been applied. Security teams and vulnerability management teams should also prioritize verifying and patching Keycloak instances to prevent this.

Why it matters

A flaw in Keycloak's policy enforcer allows an authenticated user to trick the enforcer into applying a less restrictive security policy than intended, potentially gaining unauthorized access to sensitive administrative or private application endpoints. Defenders should prioritize verifying and patching Keycloak instances to prevent unauthorized access.

• Verify and patch Keycloak instances to prevent unauthorized access
• Review and update Keycloak configurations and user access controls
• Monitor for suspicious activity on Keycloak-protected applications

Technical summary

The Keycloak policy enforcer fails to correctly normalize web addresses containing special encoded characters, allowing an authenticated user to bypass intended security policies and potentially access sensitive endpoints. This flaw can be exploited by using special encoded characters in web addresses to trick the enforcer into applying a less restrictive security policy than intended. Defenders should prioritize verifying and patching Keycloak instances to prevent unauthorized access and review Keycloak configurations and user access controls.

Defensive priority

Defenders should prioritize verifying and patching Keycloak instances to prevent unauthorized access. Assess exposure by reviewing Keycloak configurations and user access controls.

Recommended defensive actions

• Verify and apply patches for Keycloak instances
• Review Keycloak configurations and user access controls
• Monitor for suspicious activity on Keycloak-protected applications
• Perform vulnerability scanning to identify exposed Keycloak instances
• Review compensating controls for exposed systems while remediation is scheduled and verified
• Check relevant monitoring, detection, and logs for exposed assets that need extra review
• Track exceptions, retest remediated assets, and close the item only after evidence is documented

Evidence notes

The CVE record and NVD entry provide details on the flaw in Keycloak's policy enforcer. Red Hat has released errata related to this vulnerability. The flaw allows an authenticated user to bypass intended security policies and potentially access sensitive endpoints by exploiting special encoded characters in web addresses. Defenders should verify and patch Keycloak instances to prevent unauthorized access. Evidence is limited to CVE and NVD details; further verification is recommended.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.