CVE-2026-117691
Keycloak-services: keycloak-services: saml redirect binding signature bypass via percent-encoded parameter names
A flaw was found in the SAML HTTP-Redirect binding implementation of Keycloak. The issue occurs because the server processes percent-encoded parameter names (like %53AMLResponse) while the signature verification logic only checks literal parameter names. An attacker can use this discrepancy to provide a crafted, unsigned SAML message that the server processes instead of a legitimately signed one, leading to full account takeover of federated users.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
Keycloak-services: keycloak-services: saml redirect binding signature bypass via percent-encoded parameter names
A flaw was found in the SAML HTTP-Redirect binding implementation of Keycloak. The issue occurs because the server processes percent-encoded parameter names (like %53AMLResponse) while the signature verification logic only checks literal parameter names. An attacker can use this discrepancy to provide a crafted, unsigned SAML message that the server processes instead of a legitimately signed one, leading to full account takeover of federated users.
- Record
CVE-2026-117691- CVSS 3.1
- 9.1 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N - Weakness
- CWE-347
- Updated
- 2026-11-07
EUVDEUVD-2026-117441
A flaw was found in the SAML HTTP-Redirect binding implementation of Keycloak. The issue occurs because the server processes percent-encoded parameter names (like %53AMLResponse) while the signature verification logic only checks literal parameter names. An attacker can use this discrepancy to provide a crafted, unsigned SAML message that the server processes instead of a legitimately signed one, leading to full account takeover of federated users.
- Record
EUVD-2026-117441- CVSS 3.1
- 9.1 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N - Updated
- 2026-11-07
GitHub AdvisoriesGHSA-c85j-3hq2-q6wj
A flaw was found in the SAML HTTP-Redirect binding implementation of Keycloak. The issue occurs...
A flaw was found in the SAML HTTP-Redirect binding implementation of Keycloak. The issue occurs because the server processes percent-encoded parameter names (like %53AMLResponse) while the signature verification logic only checks literal parameter names. An attacker can use this discrepancy to provide a crafted, unsigned SAML message that the server processes instead of a legitimately signed one, leading to full account takeover of federated users.
- Record
GHSA-c85j-3hq2-q6wj- CVSS 3.1
- 9.1 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N - Weakness
- CWE-347
- Updated
- 2026-11-07
NVD
A flaw was found in the SAML HTTP-Redirect binding implementation of Keycloak. The issue occurs because the server processes percent-encoded parameter names (like %53AMLResponse) while the signature verification logic only checks literal parameter names. An attacker can use this discrepancy to provide a crafted, unsigned SAML message that the server processes instead of a legitimately signed one, leading to full account takeover of federated users.
- Record
CVE-2026-117691- CVSS 3.1
- 9.1 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N - Weakness
- CWE-347
- Updated
- 2026-11-07
Affected products
Public exploits
Links only. Every CVE stores no exploit code.
| Source | Link | Date |
|---|---|---|
| PoC in GitHub | foxcornlab/keycloak-saml-scanner | 2026-11-07 |
History
| Recorded | Changed | Sources |
|---|---|---|
| exploits, facts | EUVD, PoC in GitHub | |
| products, references | CVE List, EUVD, GitHub Advisories | |
| products, references | CVE List, EUVD, NVD | |
| first indexed | CVE List, EUVD, GitHub Advisories |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-117691 is a critical vulnerability (CVSS 9.1) in Red Hat Build Of Keycloak 26.6, published November 5, 2026. Public exploit code exists. EPSS puts the chance of exploitation in the next 30 days at 0.26%, the 18th percentile. No source names a fixed version.