Red Hat Build of Keycloak: Improper Verification of Cryptographic Signature (CVE-2026-117691)
Published Last modified Sources: pwn.watch, CVE.org
What is affected, what to do
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.
The available sources name no fixed version. Check the vendor guidance in the references below.
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Metrics
9.1
Priority
XIEM Effective CVSS: highest available CVSS rating from NVD and vendor data.
Source: NVD, CVSS v3
9.1
CVSS v3
Severity Critical on the scale from 0 to 10.
Source: pwn.watch, CVE.org
—
EPSS score
No value is available for this vulnerability.
Show all metrics
- Severity
- Critical
Priority (0–325)
The priority score is a consolidated metric that condenses several individual signals into a single, action-guiding ranking: technical severity (CVSS), exploitation likelihood (EPSS), known-exploited status (KEV) and the context of the affected asset. The aim is to answer the only truly important question in vulnerability management: what first?
Read in glossary- 75.50 Methodology
Exploit maturity
An exploit is code or a technique that specifically uses a concrete vulnerability to force unintended behaviour — such as executing code or escalating privileges. It is the tool that turns a theoretical flaw into a practical attack.
Read in glossary- no public PoC known
XIEM Effective CVSS
XIEM® is the tiered managed-security operating model from NEOSEC and a registered trademark of NEOSEC GmbH. It extends classic SIEM — the central collection, normalisation and correlation of security-relevant events — with endpoint forensics, network visibility and deception technology, and consolidates them into three building tiers: Sentry, Orchestrate and Command.
Read in glossary- 9.1 Methodology
CVSS v3
CVSS is the globally established, open standard for assessing the technical severity of a vulnerability on a scale from 0 to 10. It describes how easily a flaw can be exploited and what damage it can cause — but not how likely its actual exploitation is. CVSS and the complementary EPSS deliberately answer different questions.
Read in glossary- 9.1
KEV status
The KEV catalogue is a list maintained by the US authority CISA of vulnerabilities for which active exploitation in the wild has been confirmed. It answers not the question „how severe?“ but „is it already being attacked?“ — thereby sharply prioritising patching.
Read in glossary- —
- Published
- CISA assessment (SSVC)
- Exploitation: none known · automatable · Technical impact: total
- Source: CISA Vulnrichment, as of 5 November 2026
CWE
CWE is a catalogue of typical weakness types in software and hardware — such as flawed input validation, unsafe memory handling or poor authentication. Where a CVE names a concrete vulnerability in a concrete product, a CWE describes the underlying class of defect.
Read in glossary- CWE-347
Detection rules
No NEOSEC detection rule is available for this vulnerability yet.
Classification under NIS2 and CRA
Rule-based classification from exploitation status and severity. It does not replace a case-by-case assessment.
NIS2
NIS2 is EU Directive (EU) 2022/2555 to raise the level of cybersecurity across the Union. It substantially broadens obligations compared with the first NIS directive: more sectors, mandatory risk management, staged reporting duties and personal accountability of senior management.
Read in glossary- High technical severity: assess and remediate the vulnerability in vulnerability handling under Art. 21(2)(e) NIS2 and document the decision.
CRA
The CRA is EU Regulation (EU) 2024/2847 setting horizontal cybersecurity requirements for „products with digital elements“ — from industrial controllers and software to connected consumer devices. For the first time manufacturers must ensure security across the entire product lifecycle, handle vulnerabilities and provide security updates.
Read in glossary- From 11.12.2027, Annex I Part II CRA requires manufacturers of affected products with digital elements to handle vulnerabilities without delay and provide security updates.
ISO/IEC 27001
ISO/IEC 27001 is the internationally leading standard for an information security management system (ISMS). It describes a risk-based, process-oriented framework to systematically plan, implement, review and improve information security.
Read in glossary- Control A.8.8, management of technical vulnerabilities: assess relevance to your systems, plan remediation and keep evidence.
Description
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.
Source: pwn.watch, NVD (NIST), cvelistv5
Affected products
The following versions are affected. Older releases of the same product line are also vulnerable unless stated otherwise.
| Affected versions | Fixed in | ||
|---|---|---|---|
| Red Hat | Red Hat Build of Keycloak |
|
|
| Red Hat | Red Hat Single Sign-On 7 |
|
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Vendors and products
Weakness classes (CWE)
CWE-347Improper Verification of Cryptographic Signature
Base
The product does not verify, or incorrectly verifies, the cryptographic signature for data.
Entry at MITRE CWE-347
References & sources
- access.redhat.comCVE-2026-117691pwn-watch, Vulnerability database, x_refsource_REDHAT
- bugzilla.redhat.comBugzilla 2561977: SAML redirect binding signature bypass via percent-encoded parameter namespwn-watch, Issue tracking, x_refsource_REDHAT
- pwn.watchpwn.watch: Keycloak SAML redirect-binding signature bypass lets attackers take over federated accounts (CVE-2026-117691)pwn-watch
- CVE.org (MITRE)CVE-2026-117691pwn-watch
- github.comKeycloak 26.8.2pwn-watch
- github.comVerify the SAML redirect binding message that is processed (closes CVE-2026-117691)pwn-watch
Changes to this CVE
Who changed this CVE and when: NVD (analysis, affected products, CVSS), the CVE publisher (CNA) and additional providers such as CISA (ADP).
Record modifiedCISA ADP
CISA assessment (SSVC): exploitation: none known, automatable: yes
Show the original change
Individual changes of this event as published by NVD Type Action Before After SSVC assessment added —{"id":"CVE-2026-117691","role":"CISA Coordinator","options":[{"exploitation":"none"},{"automatable":"yes"},{"technicalImpact":"total"}],"version":"2.0.3","timestamp":"2026-11-05T16:28:53.520705Z"}Source identifier: 134c704f-9b21-4f2e-91b3-4a467353bcc0
ReceivedRed Hat
CVSS V3.1: AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
Weakness type: CWE-347
Description added or changed
Show 6 original changes
Individual changes of this event as published by NVD Type Action Before After Description added —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.CVSS added —AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:NWeakness type (CWE) added —CWE-347Affected versions (publisher) added —New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/117xxx/CVE-2026-117691.json">CVE-2026-117691</a>Reference added —https://access.redhat.com/security/cve/CVE-2026-117691Reference added —https://bugzilla.redhat.com/show_bug.cgi?id=2561977Source identifier: secalert@redhat.com
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<a href="https://intel.neosec.eu/en/cve/CVE-2026-117691"><img src="https://intel.neosec.eu/badge/cve/CVE-2026-117691.svg?lang=en" alt="CVE-2026-117691 – NEOSEC Intel" height="20"></a>