CVE-2026-9793
Keycloak: keycloak: security policy bypass in jwe-encrypted request object processing
- State
- Published
- Severity
- 5.9 Medium
- Published
- May 28, 2026
- Updated
- Aug 20, 2026
- Reserved
- May 28, 2026
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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 3.1 | 5.9 Medium | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N | redhat |
Weaknesses
- CWE-347 Improper Verification of Cryptographic Signature
Affected Products
| Product | Versions |
|---|---|
Red Hat build of Keycloak 26.4Red Hat |
|
Red Hat build of Keycloak 26.4Red Hat |
|
Red Hat build of Keycloak 26.4Red Hat |
|
Red Hat build of Keycloak 26.4.14Red Hat | |
Red Hat build of Keycloak 26.6Red Hat |
|
Red Hat build of Keycloak 26.6Red Hat |
|
Red Hat build of Keycloak 26.6Red Hat |
|
Red Hat build of Keycloak 26.6.5Red Hat |
References
- RHSA-2026:50846vendor-advisory
- RHSA-2026:50847vendor-advisory
- RHSA-2026:50848vendor-advisory
- RHSA-2026:50849vendor-advisory
- https://access.redhat.com/security/cve/CVE-2026-9793vdb-entry
- RHBZ#2482460issue-tracking
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