Description
A SAML authentication bypass vulnerability affects the Kong SAML plugin when the validate_assertion_signature option is explicitly set to false. This option is enabled by default. When disabled, the plugin may extract the SAML identity from an unsigned assertion and authenticate the user without verifying a valid cryptographic signature. As a result, an unauthenticated remote attacker may be able to submit a crafted SAML response and impersonate arbitrary users, including administrators
References1
Metrics
- CVSS 4.0
-
7.7
HIGH
Score source: CNA
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:H/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - EPSS — exploit probability
- 1% percentile: 58 · as of 7 November 2026
- CWE
- CWE-288
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.