Public vulnerability disclosure

CVE-2026-97846

Keycloak-services: keycloak-services: standard token exchange v2 bypasses mtls holder-of-key binding

publishedCWE-287

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.

Technical severity6.8 mediumCVSS 3.1 · CNA: redhat
Published2026-09-25Source updated 2026-11-06
Collected2026-11-062 attributed sources

Fixes and workarounds

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

Affected products, source version ranges and reporting authorities
ProductVersionsAuthority
Red Hat build of Keycloak 26.6.8
Red Hat
keycloak-services
https://access.redhat.com/downloads/content/package-browser/
Range not reported
Other versions: unaffected
CNA: redhat
Red Hat build of Keycloak 26.6.8
Red Hat
rhbk/keycloak-rhel9
https://access.redhat.com/downloads/content/package-browser/
Range not reported
Other versions: unaffected
CNA: redhat
Red Hat Single Sign-On 7
Red Hat
keycloak-services
https://access.redhat.com/downloads/content/package-browser/
Range not reported
Other versions: unaffected
CNA: redhat

Version ranges are source assertions. Check the vendor advisory and your installed configuration before determining exposure.

CVSS assessments

CVSS scores, vectors and reporting authorities
Version / scoreVectorAuthority
3.1 / 6.8
medium
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:NCNA: redhat

Exploit evidence

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

References

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