CVE-2026-9793

HIGH

MEDIUM Priority: 0.01 BB Relevance: 75/100

Published: 2026-05-28 Modified: 2026-10-26 First seen: 2026-10-29 Status: active

Attack Surface

Network Low Complexity No Auth No Interaction Integ. Impact

CVSS Vector Breakdown

AV: Network

AC: Low

PR: None

UI: None

S: Unchanged

C: None

I: High

A: None

Description

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.