Vulnerability · Published Sep 25, 2026 · Assigned by redhat

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

Medium 6.8

In plain English

A medium-severity improper authentication in Red Hat Build of Keycloak from Red Hat. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.1% (higher than 3% of all known vulnerabilities).

Severity (CVSS 3.1)6.8Medium

Exploit odds (30 days)0.1%top 97.0% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

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.

Affected products (as reported)

Vendor	Product	Versions
Red Hat	Red Hat Build of Keycloak	see references
Red Hat	Red Hat Build of Keycloak	see references
Red Hat	Red Hat Single Sign-On 7	see references

Weakness: CWE-287 · Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N

References

https://access.redhat.com/security/cve/CVE-2026-97846 vdb-entry, x_refsource_REDHAT
RHBZ#2540949 issue-tracking, x_refsource_REDHAT