# CVE-2026-9793: Keycloak signature policy bypass in JWE-encrypted request objects

Source: https://junglewise.ai/threats/cve-2026-9793-keycloak-signature-policy-bypass-in-jwe-encrypted-request-objects  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-05-28. Updated: 2026-07-01  
License: CC BY 4.0 with a link back

CVE-2026-9793 · Severity: medium · CVSS 5.9 · Published 2026-05-28

Keycloak, an open-source identity and access management solution, contains a flaw in how it handles encrypted login requests. An attacker could bypass security policies to submit unauthorized data during the login process, potentially compromising the integrity of user authentication. While existing security controls like redirect allowlists provide some protection, this issue allows for the submission of unsigned data that should otherwise be rejected.

Technologies: [Keycloak](https://junglewise.ai/threats/technologies/keycloak), [org.keycloak:keycloak-services (Maven)](https://junglewise.ai/threats/technologies/org-keycloak-keycloak-services), [Red Hat build of Keycloak](https://junglewise.ai/threats/technologies/red-hat-keycloak). Vendors: [Keycloak](https://junglewise.ai/threats/vendors/keycloak), [Maven](https://junglewise.ai/threats/vendors/maven), [Red Hat](https://junglewise.ai/threats/vendors/red-hat).

## Quick answers

**Is CVE-2026-9793 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-9793 being exploited in the wild.

**How severe is CVE-2026-9793?** Medium severity, with a CVSS score of 5.9, published 28 May 2026.

**Which products and versions are affected?** Keycloak <= 26.6.4; org.keycloak:keycloak-services (Maven) <= 26.6.4, ECOSYSTEM:introduced=0,last_affected=26.6.4; Red Hat build of Keycloak -.

**Is there a fix for CVE-2026-9793?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-9793 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-9793?** Check whether you run Keycloak, org.keycloak:keycloak-services (Maven) or Red Hat build of Keycloak at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

An improper verification of cryptographic signatures (CWE-347) exists in Keycloak's OIDC request object processing. When a JSON Web Encryption (JWE) encrypted request object is submitted, Keycloak may decrypt the content and process it as raw JSON without enforcing the configured 'requestObjectSignatureAlg' policy. This allows an attacker to bypass mandatory signing requirements (such as RS256) by wrapping unsigned claims in a JWE envelope. The vulnerability violates OIDC Core and FAPI requirements, though impact is partially mitigated by redirect URI allowlists. As of the advisory, no patch is explicitly confirmed for version 26.6.4.

## Affected products

- Keycloak Keycloak <= 26.6.4
- Red Hat Red Hat Build of Keycloak -

## Identifiers

- CVE-2026-9793
- GHSA-p3v8-fm5p-v84h

## Timeline

- 2026-05-28: disclosed: Vulnerability reported and GHSA published
- 2026-05-28: advisory: NVD and Red Hat advisories published

## References

- [https://access.redhat.com/security/cve/CVE-2026-9793](https://access.redhat.com/security/cve/CVE-2026-9793)
- [https://bugzilla.redhat.com/show_bug.cgi?id=2482460](https://bugzilla.redhat.com/show_bug.cgi?id=2482460)
- [https://github.com/keycloak/keycloak/issues/49429](https://github.com/keycloak/keycloak/issues/49429)

## Related threats

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- [Keycloak server arbitrary code execution in client authorization](https://junglewise.ai/threats/cve-2026-120984-a-flaw-was-found-in-the-keycloak-server-s-client-management)
- [Keycloak token sanitization bypass in protocol mapper](https://junglewise.ai/threats/cve-2026-97848-a-flaw-was-found-in-the-token-sanitization-logic-of-keycloak-an)
- [Keycloak Dynamic Client Registration privilege escalation](https://junglewise.ai/threats/cve-2026-96547-a-flaw-was-found-in-the-dynamic-client-registration-component-of)