medium5.9
CVE-2026-9793
Keycloak has an Improper Verification of Cryptographic Signature issue
Impact
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.
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| maven | org.keycloak:keycloak-services | <= 26.6.4 | none recorded |
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Redhat | Build Of Keycloak | All versions |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- https://github.com/advisories/GHSA-p3v8-fm5p-v84h
- https://nvd.nist.gov/vuln/detail/CVE-2026-9793
- https://access.redhat.com/security/cve/CVE-2026-9793
- https://bugzilla.redhat.com/show_bug.cgi?id=2482460
- https://github.com/keycloak/keycloak/issues/49429
- https://access.redhat.com/errata/RHSA-2026:50846
- https://access.redhat.com/errata/RHSA-2026:50847
- https://access.redhat.com/errata/RHSA-2026:50848
- https://access.redhat.com/errata/RHSA-2026:50849