Vulnerability in hono (CVE-2026-56762)
Summary
Vulnerability in hono (CVE-2026-56762). Risk of unauthorized operations or information disclosure. Exploitable via Cookie header. Mitigation: upgrade to 4.12.12 or later.
Original description
The description as published by the source.
Hono before 4.12.12 does not validate cookie names on the write path in the setCookie(), serialize(), and serializeSigned() functions, allowing invalid characters such as control characters (e.g. \r or \n) when an application passes a user-controlled cookie name. This can produce malformed Set-Cookie header values. In modern runtimes such as Node.js and Cloudflare Workers, such invalid header values are rejected and cause a runtime error before the response is sent, so header injection or response splitting could not be reproduced; the issue primarily affects correctness and robustness, resulting in runtime errors (availability) rather than confirmed header injection.
Source: NIST National Vulnerability Database 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-2026-56762 has been found in hono.
Attackers can target a specific entry point like Cookie header over the network to misuse the product.
Risk of unauthorized operations or information disclosure. CVSS score: 5.3/10.
What to do: upgrade hono to 4.12.12 or later.
If unsure, ask your IT team or search "hono CVE-2026-56762" on the vendor's site.
CVE-2026-56762 (hono) — CWE-20 / CVSS v3 5.3
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Attack surface: Cookie header
Patched: 4.12.12 — 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-20) exists in hono. Attackers reach the vulnerable code path via Cookie header without authentication.
Check the vendor advisory for the affected versions of hono. Attack surface: Cookie header.
Severity: Medium (CVSS 5.3/10). Risk of unauthorized operations or information disclosure.
Update to 4.12.12.
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 4.12.12ステージング環境で 4.12.12 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 vulncheck.com
- advisory nvd.nist.gov
- advisory github.com
- web github.com
- web github.com
- web github.com
- web github.com