Is there a public exploit for CVE-2026-11800?

No public exploit for CVE-2026-11800 was found in Exploit-DB, Metasploit, Nuclei templates or public proof-of-concept repositories. That is an absence of evidence rather than proof that none exists.

How severe is CVE-2026-11800?

CVE-2026-11800 scores CVSS 8.1 (v3.1), rated high. EPSS puts the chance of exploitation in the next 30 days at 0.3%.

What does CVE-2026-11800 affect?

CVE-2026-11800 affects Red Hat org.keycloak:keycloak-services.

8.1 High

Keycloak has authentication bypass via jwt algorithm confusion

CVE-2026-11800

Description A flaw was found in Keycloak. This JWT algorithm confusion vulnerability in the JWT Authorization Grant flow allows an attacker with valid client credentials to bypass signature verification. By forging an assertion, the attacker can create unauthorized access tokens. This enables the attacker to impersonate any federated user linked to the affected Identity Provider, leading to unauthorized access and potential privilege escalation.

Assessment

CVSS: 8.1 (v3.1)
Severity: High
EPSS: 0.3% chance of exploitation in the next 30 days
Known exploited: Not listed in CISA KEV
Exploit availability: Nothing found in Exploit-DB, Metasploit, Nuclei or public PoC repositories
Published: 3 November 2026
Last updated: 3 November 2026
Affected: Red Hat · Red Hat build of Keycloak 26.6 · org.keycloak:keycloak-services
Weakness: CWE-347
Assigner: redhat

CVSS vectorCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N

At the source

References

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