Vulnerability Description
Versions of the package @koa/router from 14.0.0 and before 15.0.0 are vulnerable to Access Control Bypass due to the middleware being silently dropped from the execution chain when the router prefix contains path parameters. Depending on what the skipped middleware was supposed to protect, an attacker could bypass authentication and authorization, evade rate limiting or bypass input sanitization.
CVSS Score
HIGH
Related Weaknesses (CWE)
References
- https://github.com/koajs/router/commit/d53e17f284557b1f417946f9807ee52290c3c759
- https://github.com/koajs/router/issues/202
- https://github.com/koajs/router/pull/206
- https://security.snyk.io/vuln/SNYK-JS-KOAROUTER-12215044
- https://github.com/koajs/router/pull/206
FAQ
What is CVE-2026-9495?
CVE-2026-9495 is a vulnerability with a CVSS score of 7.3 (HIGH). Versions of the package @koa/router from 14.0.0 and before 15.0.0 are vulnerable to Access Control Bypass due to the middleware being silently dropped from the execution chain when the router prefix c...
How severe is CVE-2026-9495?
CVE-2026-9495 has been rated HIGH with a CVSS base score of 7.3/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-9495?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.