CVE-2026-107623 Red Hat CVE debrief

Who should care

Defenders responsible for Keycloak configurations and security should assess exposure and prioritize verification and updates. This includes reviewing current configurations, verifying offline token revocation settings, and ensuring that Keycloak is updated to a version that addresses the flaw. Additionally, defenders should monitor for potential misuse of offline tokens and review compensating controls for exposed systems.

Why it matters

CVE-2026-107623 is a medium-severity flaw in Keycloak's OIDC DCR component that can cause offline token revocation settings to be silently disabled, potentially leaving offline tokens valid after user session termination. Defenders responsible for Keycloak configurations should assess exposure and prioritize verification and updates.

• Defenders must verify offline token revocation settings are properly enabled
• Potential for offline tokens to remain valid after user session termination
• Need for updates to Keycloak configurations to address the flaw

Technical summary

The flaw in Keycloak's OIDC DCR component causes the backchannel logout offline token revocation setting to be omitted from responses. This can lead to offline tokens remaining valid after a user session is terminated. The issue arises from a bug in the response serialization, which omits the backchannel logout setting during standard updates. As a result, offline tokens may remain valid even after backchannel logout, potentially exposing systems to unauthorized access. Defenders should prioritize verifying and updating Keycloak configurations.

Defensive priority

Defenders should prioritize verifying and updating Keycloak configurations to ensure offline token revocation is properly enabled.

Recommended defensive actions

• Verify Keycloak configurations to ensure offline token revocation is properly enabled
• Update Keycloak to a version that addresses the flaw, if available
• Monitor for potential misuse of offline tokens
• 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
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up

Evidence notes

The CVE record and source item provide details on the flaw in Keycloak's OIDC DCR component. However, specific affected versions and remediation steps are not provided. Defenders should verify offline token revocation settings and prioritize updates to Keycloak configurations. The source item and CVE record offer limited information on the vulnerability, and further verification is necessary to assess exposure and implement mitigations.

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.