# CVE-2026-97846: Keycloak mTLS holder-of-key binding bypass in Standard Token Exchange

Source: https://junglewise.ai/threats/cve-2026-97846-keycloak-provides-a-feature-called-mtls-holder-of-key-binding  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-09-25. Updated: 2026-09-26  
License: CC BY 4.0 with a link back

CVE-2026-97846 · Severity: medium · CVSS 6.8 · Published 2026-09-25

Keycloak is an open-source identity and access management system that authenticates users and issues security tokens. A flaw in the Standard Token Exchange V2 feature fails to verify a client's certificate, allowing an attacker with stolen credentials to obtain tokens that bypass mTLS security restrictions. This could enable unauthorized access to applications and data that rely on certificate-based authentication.

Technologies: [Red Hat build of Keycloak](https://junglewise.ai/threats/technologies/red-hat-keycloak). Vendors: [Red Hat](https://junglewise.ai/threats/vendors/red-hat).

## Quick answers

**Is CVE-2026-97846 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-97846 being exploited in the wild.

**How severe is CVE-2026-97846?** Medium severity, with a CVSS score of 6.8, published 25 September 2026.

**Which products and versions are affected?** Red Hat build of Keycloak <UNKNOWN>; Red Hat Keycloak <UNKNOWN>.

**Is there a fix for CVE-2026-97846?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-97846 attacked?** It is attacked over the network.

**Am I affected by CVE-2026-97846?** Check whether you run Red Hat build of Keycloak or Red Hat Keycloak at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

The Standard Token Exchange V2 grant provider in Keycloak does not enforce verification of client certificates when issuing tokens, violating the mTLS holder-of-key binding mechanism that should tie tokens to specific client certificates. Exploitation requires the attacker to possess valid client credentials and a valid subject token in a non-default configuration. Successful exploitation allows bypassing sender-constraints and obtaining unrestricted Bearer tokens that can be used outside the context of the original client's certificate.

## Affected products

- Red Hat Keycloak <UNKNOWN>
- Red Hat build of Keycloak <UNKNOWN>

## Timeline

- 2026-09-25: disclosed

## References

- [https://access.redhat.com/downloads/content/package-browser/](https://access.redhat.com/downloads/content/package-browser/)
- [https://access.redhat.com/security/cve/CVE-2026-97846](https://access.redhat.com/security/cve/CVE-2026-97846)

## Related threats

- [Red Hat Keycloak missing authorization check in group reparenting](https://junglewise.ai/threats/cve-2026-116468-a-flaw-was-found-in-the-group-move-and-organization-group)
- [Keycloak server arbitrary code execution in client authorization](https://junglewise.ai/threats/cve-2026-120984-a-flaw-was-found-in-the-keycloak-server-s-client-management)
- [Keycloak privilege escalation via client authentication manipulation](https://junglewise.ai/threats/cve-2026-9797-a-flaw-was-found-in-keycloak-s-administrative-services-org)
- [Keycloak Account REST API session manipulation](https://junglewise.ai/threats/cve-2026-97367-a-flaw-was-found-in-the-keycloak-account-rest-api-where-it)
- [Keycloak token exchange lifetime bypass in Standard Token Exchange V2](https://junglewise.ai/threats/cve-2026-96460-a-flaw-was-found-in-the-token-exchange-mechanism-of-keycloak-when)