CVSS 3.1
9.1 criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:NCVE-2026-117691
Critical (9.1).
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.
Severity
- CWE
- CWE-347 Improper Verification of Cryptographic Signature
- OWASP Top 10
- A04:2025 Cryptographic Failures
- Published
- Modified
- Record from
- the NVD, synced
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Explain CVE-2026-117691 for an engineer deciding whether to act. Use https://cve.bz/api/public/cves/CVE-2026-117691?via=ask-ai-copy and https://cve.bz/cve/CVE-2026-117691?via=ask-ai-copy as the source of truth: what is affected and which versions fix it, whether it is in CISA KEV, public exploits, and its EPSS (an internet-wide 30-day estimate of exploitation activity, not a forecast for my systems). If they give no fixed versions, use the CVE record https://cveawg.mitre.org/api/cve/CVE-2026-117691 or the vendor advisory, not third-party mirrors. Tell me how to check whether I am affected and how to verify a fix. Cite the sources and say where they are uncertain.Opens a third-party assistant; its answer is its own, not cve.bz's. The prompt holds only this CVE's id and public links.
Attack patterns (CAPEC)
- CAPEC-463 Padding Oracle Crypto Attack Severity: High
- CAPEC-475 Signature Spoofing by Improper Validation Likelihood: Low · Severity: High
The attack patterns MITRE's CAPEC relates to this record's weaknesses, as MITRE names them. Credits.