Description
A JWT signature verification vulnerability affects Kong components that perform JWT validation for MCP OAuth2 or DataKit integrations inside Kong API Gateway Enterprise. The affected code does not properly validate that the JWT signing algorithm is compatible with the type of key used for verification. As a result, an unauthenticated remote attacker may be able to craft a forged JWT that is incorrectly accepted as valid, leading to authentication bypass and potential compromise of confidentiality, integrity, and availability.
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: 53 · as of 7 November 2026
- CWE
- CWE-241
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.