# CVE-2026-117691: Keycloak SAML signature bypass via percent-encoded parameters

Source: https://junglewise.ai/threats/cve-2026-117691-a-flaw-was-found-in-the-saml-http-redirect-binding  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-11-05. Updated: 2026-11-05  
License: CC BY 4.0 with a link back

CVE-2026-117691 · Severity: critical · CVSS 9.1 · Published 2026-11-05

Keycloak is an open-source identity and access management system used to authenticate users and manage federated login across organizations. A flaw in its SAML authentication implementation allows attackers to bypass signature verification by submitting percent-encoded parameter names, enabling complete account takeover of any federated user without needing valid credentials. This affects organizations using Keycloak for single sign-on and federated identity.

Technologies: [Red Hat Keycloak](https://junglewise.ai/threats/technologies/red-hat-keycloak). Vendors: [Red Hat](https://junglewise.ai/threats/vendors/red-hat).

## Quick answers

**Is CVE-2026-117691 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-117691 being exploited in the wild.

**How severe is CVE-2026-117691?** Critical severity, with a CVSS score of 9.1, published 5 November 2026.

**Which products and versions are affected?** Red Hat Keycloak.

**Is there a fix for CVE-2026-117691?** 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-2026-117691 attacked?** It is attacked over the network, in a web application.

**Am I affected by CVE-2026-117691?** Check whether you run Red Hat Keycloak. 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

The vulnerability exists in the SAML HTTP-Redirect binding where the signature verification logic checks literal parameter names (e.g., "SAMLResponse") but the message processing logic also accepts percent-encoded variants (e.g., "%53AMLResponse"). An unauthenticated attacker can craft an unsigned SAML message with percent-encoded parameter names to bypass signature validation, allowing account takeover of any federated user. The root cause is inconsistent parsing of query parameters between two code paths (CWE-347).

## Affected products

- Red Hat Keycloak

## References

- [https://access.redhat.com/downloads/content/package-browser/](https://access.redhat.com/downloads/content/package-browser/)
- [https://access.redhat.com/security/cve/CVE-2026-117691](https://access.redhat.com/security/cve/CVE-2026-117691)

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