CVE-2026-9495
Summary
| CVE | CVE-2026-9495 |
|---|---|
| State | PUBLISHED |
| Assigner | snyk |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-05-26 07:16:19 UTC |
| Updated | 2026-05-26 20:16:40 UTC |
| 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. |
Risk And Classification
Primary CVSS: v4.0 5.5 MEDIUM from [email protected]
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
EPSS: 0.000860000 probability, percentile 0.248610000 (date 2026-05-31)
Problem Types: CWE-284 | CWE-284 Access Control Bypass | CWE-284 CWE-284 Improper Access Control
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 4.0 | [email protected] | Secondary | 5.5 | MEDIUM | 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/C... |
| 4.0 | CNA | DECLARED | 6.9 | MEDIUM | 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 |
| 3.1 | [email protected] | Secondary | 7.3 | HIGH | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L |
| 3.1 | CNA | DECLARED | 7.3 | HIGH | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L/E:P |
CVSS v4.0 Breakdown
Attack Vector
NetworkAttack Complexity
LowAttack Requirements
NonePrivileges Required
NoneUser Interaction
NoneConfidentiality
LowIntegrity
LowAvailability
LowSub Conf.
NoneSub Integrity
NoneSub Availability
NoneCVSS: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
CVSS v3.1 Breakdown
Attack Vector
NetworkAttack Complexity
LowPrivileges Required
NoneUser Interaction
NoneScope
UnchangedConfidentiality
LowIntegrity
LowAvailability
LowCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Na | @koa/router | affected 14.0.0 15.0.0 semver | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| security.snyk.io/vuln/SNYK-JS-KOAROUTER-12215044 | [email protected] | security.snyk.io | |
| github.com/koajs/router/pull/206 | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | github.com | |
| github.com/koajs/router/issues/202 | [email protected] | github.com | |
| github.com/koajs/router/commit/d53e17f284557b1f417946f9807ee52290c3c759 | [email protected] | github.com | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Vendor Comments And Credit
Discovery Credit
CNA: Ryan Mitchell (en)
There are currently no legacy QID mappings associated with this CVE.