Vulnerability in hono (CVE-2026-56763)
Summary
Vulnerability in hono (CVE-2026-56763). Risk of unauthorized operations or information disclosure. Exploitable via __proto__.x. Mitigation: upgrade to 4.12.7 or later.
Original description
The description as published by the source.
Summary
When using parseBody({ dot: true }) in HonoRequest, specially crafted form field names such as __proto__.x could create objects containing a __proto__ property.
If the parsed result is later merged into regular JavaScript objects using unsafe merge patterns, this may lead to prototype pollution in the target object.
Details
The parseBody({ dot: true }) feature supports dot notation to construct nested objects from form field names.
In previous versions, the __proto__ path segment was not filtered. As a result, specially crafted keys such as __proto__.x could produce objects containing __proto__ properties.
While this behavior does not directly modify Object.prototype within Hono itself, it may become exploitable if the parsed result is later merged into regular JavaScript objects using unsafe merge patterns.
Impact
Applications that merge parsed form data into regular objects using unsafe patterns (for example recursive deep merge utilities) may become vulnerable to prototype pollution.
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-2026-56763 has been found in hono.
Attackers can target a specific entry point like __proto__.x over the network to misuse the product.
Risk of unauthorized operations or information disclosure. CVSS score: 4.8/10.
What to do: upgrade hono to 4.12.7 or later.
If unsure, ask your IT team or search "hono CVE-2026-56763" on the vendor's site.
CVE-2026-56763 (hono) — CWE-1321 / CVSS v3 4.8
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Attack surface: __proto__.x / __proto__ / Object.prototype
Patched: 4.12.7 — 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-1321) exists in hono. Attackers reach the vulnerable code path via __proto__.x without authentication.
Check the vendor advisory for the affected versions of hono. Attack surface: __proto__.x / __proto__ / Object.prototype.
Severity: Medium (CVSS 4.8/10). Risk of unauthorized operations or information disclosure.
Update to 4.12.7.
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 4.12.7ステージング環境で 4.12.7 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
- package github.com
- web github.com
- web vulncheck.com
- web github.com
- web github.com
- web github.com