Vulnerability in @hono/node-server (CVE-2026-73565)
Summary
Vulnerability in @hono/node-server (CVE-2026-73565). Risk of unauthorized operations or information disclosure. Exploitable via upgradeWebSocket. Mitigation: upgrade to 2.0.10 or later.
Original description
The description as published by the source.
Summary
A WebSocket upgrade request to an upgradeWebSocket route with a missing or malformed Sec-WebSocket-Key header leaks memory permanently. The request's IncomingMessage is retained in an internal map and a pending promise is never settled, even though no connection is established. Since the route is reachable pre-handshake without authentication, an unauthenticated attacker can flood it to gradually exhaust memory.
Details
The built-in WebSocket helper cleans up its internal map only on a successful handshake or when the route guard rejects the request. When ws aborts the handshake because Sec-WebSocket-Key is missing or malformed, no connection event is emitted, so neither cleanup path runs and the entry is retained forever. A present-but-malformed key leaks identically, so a proxy that only checks for the header's presence does not mitigate it.
Impact
An unauthenticated attacker can flood any public upgradeWebSocket route with malformed-key upgrade requests, causing unbounded memory growth and eventual loss of availability. No confidentiality or integrity impact.
Reported by @TarPeg007.
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-2026-73565 has been found in @hono/node-server.
Attackers can target a specific entry point like upgradeWebSocket over the network to misuse the product.
Risk of unauthorized operations or information disclosure. CVSS score: 5.3/10.
What to do: upgrade @hono/node-server to 2.0.10 or later.
If unsure, ask your IT team or search "@hono/node-server CVE-2026-73565" on the vendor's site.
CVE-2026-73565 (@hono/node-server) — CWE-401 / CVSS v3 5.3
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Attack surface: upgradeWebSocket / IncomingMessage / connection
Patched: 2.0.10 — 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-401) exists in @hono/node-server. Attackers reach the vulnerable code path via upgradeWebSocket without authentication.
Check the vendor advisory for the affected versions of @hono/node-server. Attack surface: upgradeWebSocket / IncomingMessage / connection.
Severity: Medium (CVSS 5.3/10). Risk of unauthorized operations or information disclosure.
Update to 2.0.10.
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/node-server' . 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/node-server' . | 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/node-server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/node-server to 2.0.10ステージング環境で 2.0.10 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。