# CVE-2026-97846: Keycloak-services: keycloak-services: standard token exchange v2 bypasses mtls holder-of-key binding

Status: published. Published: 2026-09-25. Updated: 2026-11-06.

Keycloak provides a feature called mTLS holder-of-key binding which ensures that a token can only be used by the client that originally requested it by binding it to their digital certificate. A flaw was discovered where the new Standard Token Exchange V2 feature does not check for this certificate. This allows an attacker with stolen client credentials to obtain a standard, unrestricted token that bypasses these security protections.

## Remediation

- workaround: Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability. (source: CNA: redhat)

## Affected products and versions

- Red Hat / Red Hat build of Keycloak 26.6.8 (keycloak-services): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat build of Keycloak 26.6.8 (rhbk/keycloak-rhel9): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat Single Sign-On 7 (keycloak-services): Version range not reported. Source: CNA: redhat

## Severity and prioritization

- CVSS 3.1: 6.8 (medium); CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N; source: CNA: redhat

- CVSS 3.1: 6.8 (medium); CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N; source: NVD: secalert@redhat.com

- CISA KEV: No listing in collected sources

- EPSS: 0.14% as of 2026-11-05; percentile 2.98%

- SSVC: exploitation none; automatable no; technical impact total; source ADP: CISA-ADP

- Weaknesses: CWE-287

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://access.redhat.com/errata/RHSA-2026:95761 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/security/cve/CVE-2026-97846 (CNA: redhat; vdb-entry, x_refsource_REDHAT)

- https://bugzilla.redhat.com/show_bug.cgi?id=2540949 (CNA: redhat; issue-tracking, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2026:95761 (secalert@redhat.com)

- https://access.redhat.com/security/cve/CVE-2026-97846 (secalert@redhat.com)

- https://bugzilla.redhat.com/show_bug.cgi?id=2540949 (secalert@redhat.com)

## Provenance

- CNA: redhat: https://www.cve.org/CVERecord?id=CVE-2026-97846; retrieved 2026-11-06; source updated 2026-11-06

- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-97846; retrieved 2026-11-06; source updated 2026-11-06

- FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2026-97846; retrieved 2026-11-06; source updated Not reported

Revision: 5ca03952c3b83b7cfd223a7f4864d8e0cc58f7aca1a04923853002149a9b5352

Canonical: https://y2.dev/cve/CVE-2026-97846

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