Vulnerability Details CVE-2026-9793
A flaw was found in Keycloak. When a JSON Web Encryption (JWE) encrypted request object is submitted, Keycloak may incorrectly process unsigned claims if the decrypted content is raw JSON, bypassing the configured signature policy. This allows a remote attacker to submit unauthorized claims, leading to a compromise of data integrity within the OpenID Connect (OIDC) authorization flow. While a redirect URI allowlist acts as a compensating control, this vulnerability violates OIDC Core and Financial-grade API (FAPI) signing requirements.
Exploit prediction scoring system (EPSS) score
EPSS Score 0.0
EPSS Ranking 2.0%
CVSS Severity
CVSS v3 Score 5.9
References
Products affected by CVE-2026-9793
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cpe:2.3:a:redhat:build_of_keycloak:-