Vulnerability in hono (CVE-2026-47675)
Summary
Vulnerability in hono (CVE-2026-47675). Risk of unauthorized operations or information disclosure. Exploitable via domain. Mitigation: upgrade to 4.12.21 or later.
Original description
The description as published by the source.
Summary
The serialize() function in hono/cookie validates domain and path options against characters that corrupt Set-Cookie header syntax (;, \r, \n), but does not apply the same validation to sameSite and priority. An application that passes user-controlled input into either option may produce a Set-Cookie response header containing attacker-chosen additional attributes.
Details
When constructing a Set-Cookie header value, serialize() appends the sameSite and priority option values directly into the output string after a presentation-only transformation (capitalizing the first character). Although the TypeScript type signature constrains these options to specific string literals, that constraint is not enforced at runtime; any string value, including one containing ; or line-feed characters, passes through unchanged.
The validation guard that rejects ;, \r, and \n from domain and path is not applied to sameSite or priority. An application that passes a request-derived value to either option therefore provides an injection point into the header line.
This issue arises when an application passes user-controlled input to the sameSite or priority option of setCookie() or serialize().
Impact
An attacker who can control the sameSite or priority option value may inject additional attributes into a Set-Cookie response header.
This may lead to:
- Cookie attribute injection — overriding
Domain,Path,…
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-2026-47675 has been found in hono.
Attackers can target a specific entry point like domain over the network to misuse the product.
Risk of unauthorized operations or information disclosure. CVSS score: 4.3/10.
What to do: upgrade hono to 4.12.21 or later.
If unsure, ask your IT team or search "hono CVE-2026-47675" on the vendor's site.
CVE-2026-47675 (hono) — CWE-113 / CVSS v3 4.3
Attack vector: remote (network-reachable) / unauthenticated
Attack surface: domain / path / sameSite / priority
Patched: 4.12.21 — 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-113) exists in hono. Attackers reach the vulnerable code path via domain without authentication.
Check the vendor advisory for the affected versions of hono. Attack surface: domain / path / sameSite / priority.
Severity: Medium (CVSS 4.3/10). Risk of unauthorized operations or information disclosure.
Update to 4.12.21.
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
-
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 4.12.21ステージング環境で 4.12.21 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
- patch security-advisories@github.com
- web github.com
- web github.com
- web github.com