CVE-2026-9495 Details
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.
A vulnerability allowing access control bypass has been identified in the @koa/router package, specifically in versions 14.0.0 prior to 15.0.0. This issue arises because middleware is silently omitted from the execution chain when the router prefix includes path parameters. As a result, an attacker could potentially bypass authentication and authorization, evade rate limiting, or circumvent input sanitization, depending on the purpose of the skipped middleware.
Upgrade @koa/router to version 15.0.0 or higher.
Metrics
CVSS 4.0 Severity and Vector Strings:
CVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
CISA-ADP
Assessed May 26, 2026References to Advisories, Solutions, and Tools
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Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-284 | Improper Access Control | CISA-ADP |
| CWE-284 | Improper Access Control | [email protected] |
Affected Products
No affected product data is available for this CVE.
Change History
5 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jul 23, 2026 | CVE Translated | [email protected] |
| Jun 17, 2026 | CVE Modified | [email protected] |
| Jun 17, 2026 | CVE Modified | CISA-ADP |
| May 26, 2026 | CVE Modified | CISA-ADP |
| May 26, 2026 | New CVE Received | [email protected] |