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CVE-2026-16729
medium
CVSS 4.8
Vulnerability in undici (CVE-2026-16729)
Summary
vulnerability in undici (CVE-2026-16729). Risk of unauthorized operations or information disclosure. Exploitable via ``setCookie``. Mitigation: upgrade to `8.9.0` or later.
AI summary snake-internal / snake-material-v2
A vulnerability tracked as **CVE-2026-16729** has been found in undici.
Attackers can target a specific entry point like ``setCookie`` over the network to misuse the product.
Risk of unauthorized operations or information disclosure. CVSS score: 4.8/10.
What to do: upgrade undici to **8.9.0** or later.
If unsure, ask your IT team or search "undici CVE-2026-16729" on the vendor's site.
CVE-2026-16729 (undici) — CWE-74 / CVSS v3 4.8
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Attack surface: `setCookie` / `validateCookieDomain` / `validateCookiePath` / `domain`
Patched: `8.9.0` — 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.
❓ What is the problem
**A vulnerability** (CWE-74) exists in undici. Attackers reach the vulnerable code path via ``setCookie`` without authentication.
📍 Affected scope
undici — . Attack surface: `setCookie` / `validateCookieDomain` / `validateCookiePath` / `domain`.
🔥 Severity
Severity: Medium (CVSS 4.8/10). Risk of unauthorized operations or information disclosure
🔧 How to fix
Update to **8.9.0**.
🛡️ Workaround
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
🔍 Detection
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run `grep -r 'undici' .` against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response Actions (7 steps)
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
grep -r 'undici' . | 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 `undici` を grep し、稼働しているサービス・バージョンを把握する。
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6Apply patch patch
Upgrade undici to 8.9.0ステージング環境で 8.9.0 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と、Step 3 で見つけた異常検知の続報チェックを含めること。
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7Post-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 Step 3 と同じログクエリでアラート再発が無いか継続監視。
Affected packages
npm
undici
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"8.9.0"}]}]
References
- patch ce714d77-add3-4f53-aff5-83d477b104bb
- patch ce714d77-add3-4f53-aff5-83d477b104bb
- web https://nvd.nist.gov/vuln/detail/CVE-2026-16729
- web https://github.com/nodejs/undici/commit/10d93fc332f2c8c161982dec3833201de29891b5
- web https://github.com/nodejs/undici/commit/3bf91ddb493e853957f3a58e155326a668ab8aef
- web https://github.com/nodejs/undici/commit/af7484043ee075a6f216da0ad77e1dac55199235
- web https://github.com/nodejs/undici/releases/tag/v6.28.0
- web https://github.com/nodejs/undici/releases/tag/v7.29.0
- web https://github.com/nodejs/undici/releases/tag/v8.9.0
- web https://github.com/advisories/GHSA-v3r7-h72x-cjcm