Path Traversal in hono (CVE-2026-54286)
Summary
Path traversal in hono (CVE-2026-54286). Confidential information can be exposed externally. Mitigation: upgrade to 4.12.25 or later.
Original description
The description as published by the source.
Hono is a Web application framework that provides support for any JavaScript runtime. Prior to 4.12.25, on Windows hosts, an encoded backslash (%5C) in the request path decodes to , which the Windows path resolver treats as a separator. serve-static then resolves a single URL segment such as admin\secret.txt into a nested file under the root and serves it, letting an attacker read static files meant to be protected behind prefix-mounted middleware. This vulnerability is fixed in 4.12.25.
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-2026-54286 has been found in hono.
Confidential information can be exposed externally. CVSS score: 5.9/10.
What to do: upgrade hono to 4.12.25 or later.
If unsure, ask your IT team or search "hono CVE-2026-54286" on the vendor's site.
CVE-2026-54286 (hono) — CWE-22 / CVSS v3 5.9
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Patched: 4.12.25 — 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.
Path traversal (CWE-22) exists in hono.
Check the vendor advisory for the affected versions of hono.
Severity: Medium (CVSS 5.9/10). Confidential information can be exposed externally.
Update to 4.12.25.
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 'hono' . 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 'hono' . | 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
hono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 hono to 4.12.25ステージング環境で 4.12.25 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 github.com
- advisory nvd.nist.gov
- advisory github.com
- web github.com