Vulnerability in @koa/router (CVE-2026-9495)
Summary
Vulnerability in @koa/router (CVE-2026-9495). Risk of unauthorized operations or information disclosure. Mitigation: upgrade to 15.0.0 or later.
Original description
The description as published by the source.
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.
Source: GitHub Security Advisories (Global) NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-9495 has been found in @koa/router.
Risk of unauthorized operations or information disclosure. CVSS score: 7.3/10.
What to do: upgrade @koa/router to 15.0.0 or later.
If unsure, ask your IT team or search "@koa/router CVE-2026-9495" on the vendor's site.
CVE-2026-9495 (@koa/router) — CWE-284 / CVSS v3 7.3
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Patched: 15.0.0 — apply immediately
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
A vulnerability (CWE-284) exists in @koa/router.
Check the vendor advisory for the affected versions of @koa/router.
Severity: High (CVSS 7.3/10). Risk of unauthorized operations or information disclosure.
Update to 15.0.0.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r '@koa/router' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
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1Identify exposure identify
grep -r '@koa/router' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
@koa/routerを grep し、稼働しているサービス・バージョンを把握する。 -
2Apply patch patch
Upgrade @koa/router to 15.0.0ステージング環境で 15.0.0 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
-
3Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Affected packages
References
- advisory nvd.nist.gov
- advisory github.com
- package github.com
- patch github.com
- patch github.com
- report github.com
- web security.snyk.io
- web github.com