Authentication Bypass by Alternate Name in kin-openapi - #VU144335

 

Authentication Bypass by Alternate Name in kin-openapi - #VU144335

Published: August 19, 2026


Vulnerability identifier: #VU144335
CSH Severity: Medium
CVSS v4: 9.1 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N]
CVE-ID: N/A
CWE-ID: CWE-289
Exploitation vector: Remote access
Exploit availability: No public exploit available

Vulnerability details

The vulnerability allows a remote attacker to bypass authentication and access a protected handler.

The vulnerability exists due to authentication bypass by alternate name in openapi3filter.ValidationHandler.Middleware when processing requests with encoded paths through a downstream router using different path interpretation semantics. A remote attacker can send a specially crafted request using an encoded path to bypass authentication and access a protected handler.

Exploitation requires the validation layer and downstream router to select different operations for the same request, such as when a public exact route and a protected parameterized route overlap after decoding and use the same HTTP method.


Affected software

kin-openapi

Remediation

Install security update from vendor's website.

kin-openapi - update to 0.147.0

External References

Related Security Bulletins