{"id":"CVE-2026-9495","sourceIdentifier":"report@snyk.io","published":"2026-05-26T07:16:19.243","lastModified":"2026-07-23T11:10:00.120","vulnStatus":"Awaiting Analysis","cveTags":[],"descriptions":[{"lang":"en","value":"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."},{"lang":"es","value":"Las versiones del paquete @koa/router desde la 14.0.0 y anteriores a la 15.0.0 son vulnerables a una omisión de control de acceso debido a que el middleware se elimina silenciosamente de la cadena de ejecución cuando el prefijo del router contiene parámetros de ruta. Dependiendo de lo que el middleware omitido debía proteger, un atacante podría omitir la autenticación y la autorización, evadir la limitación de velocidad o omitir la sanitización de entrada."}],"affected":[{"source":"report@snyk.io","affectedData":[{"vendor":"n/a","product":"@koa/router","versions":[{"version":"14.0.0","lessThan":"15.0.0","versionType":"semver","status":"affected"}]}]}],"metrics":{"cvssMetricV40":[{"source":"report@snyk.io","type":"Secondary","cvssData":{"version":"4.0","vectorString":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P/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","baseScore":5.5,"baseSeverity":"MEDIUM","attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"NONE","privilegesRequired":"NONE","userInteraction":"NONE","vulnConfidentialityImpact":"LOW","vulnIntegrityImpact":"LOW","vulnAvailabilityImpact":"LOW","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","subAvailabilityImpact":"NONE","exploitMaturity":"PROOF_OF_CONCEPT","confidentialityRequirement":"NOT_DEFINED","integrityRequirement":"NOT_DEFINED","availabilityRequirement":"NOT_DEFINED","modifiedAttackVector":"NOT_DEFINED","modifiedAttackComplexity":"NOT_DEFINED","modifiedAttackRequirements":"NOT_DEFINED","modifiedPrivilegesRequired":"NOT_DEFINED","modifiedUserInteraction":"NOT_DEFINED","modifiedVulnConfidentialityImpact":"NOT_DEFINED","modifiedVulnIntegrityImpact":"NOT_DEFINED","modifiedVulnAvailabilityImpact":"NOT_DEFINED","modifiedSubConfidentialityImpact":"NOT_DEFINED","modifiedSubIntegrityImpact":"NOT_DEFINED","modifiedSubAvailabilityImpact":"NOT_DEFINED","Safety":"NOT_DEFINED","Automatable":"NOT_DEFINED","Recovery":"NOT_DEFINED","valueDensity":"NOT_DEFINED","vulnerabilityResponseEffort":"NOT_DEFINED","providerUrgency":"NOT_DEFINED"}}],"cvssMetricV31":[{"source":"report@snyk.io","type":"Secondary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L","baseScore":7.3,"baseSeverity":"HIGH","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"LOW","integrityImpact":"LOW","availabilityImpact":"LOW"},"exploitabilityScore":3.9,"impactScore":3.4}],"ssvcV203":[{"source":"134c704f-9b21-4f2e-91b3-4a467353bcc0","ssvcData":{"timestamp":"2026-05-26T12:41:11.506721Z","id":"CVE-2026-9495","options":[{"exploitation":"poc"},{"automatable":"yes"},{"technicalImpact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}]},"weaknesses":[{"source":"report@snyk.io","type":"Secondary","description":[{"lang":"en","value":"CWE-284"}]},{"source":"134c704f-9b21-4f2e-91b3-4a467353bcc0","type":"Secondary","description":[{"lang":"en","value":"CWE-284"}]}],"references":[{"url":"https://github.com/koajs/router/commit/d53e17f284557b1f417946f9807ee52290c3c759","source":"report@snyk.io"},{"url":"https://github.com/koajs/router/issues/202","source":"report@snyk.io"},{"url":"https://github.com/koajs/router/pull/206","source":"report@snyk.io"},{"url":"https://security.snyk.io/vuln/SNYK-JS-KOAROUTER-12215044","source":"report@snyk.io"},{"url":"https://github.com/koajs/router/pull/206","source":"134c704f-9b21-4f2e-91b3-4a467353bcc0"}]}