Sign in Sign up
JA · EN · FR
SecPulse
← Back
CVE-2026-11525 low CVSS 3.7

Vulnerability in undici (CVE-2026-11525)

Summary

vulnerability in undici (CVE-2026-11525). Risk of unauthorized operations or information disclosure. Exploitable via ``SameSite``. Mitigation: upgrade to `8.5.0` or later.

AI summary snake-internal / snake-material-v2

A vulnerability tracked as **CVE-2026-11525** has been found in undici. Attackers can target a specific entry point like ``SameSite`` over the network to misuse the product. Risk of unauthorized operations or information disclosure. CVSS score: 3.7/10. What to do: upgrade undici to **8.5.0** or later. If unsure, ask your IT team or search "undici CVE-2026-11525" on the vendor's site.
CVE-2026-11525 (undici) — CWE-183 / CVSS v3 3.7 Attack vector: remote (network-reachable) / unauthenticated / no user interaction Attack surface: `SameSite` / `Strict` / `Lax` / `None` Patched: `8.5.0` — apply immediately Workaround: After parsing a `Set-Cookie` header, validate that the resulting `sameSite` attribute is one of `'Strict'`, `'Lax'`, or `'None'` (exact, case-insensitive) before forwarding or relying on it. 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-183) exists in undici. Attackers reach the vulnerable code path via ``SameSite`` without authentication.
📍 Affected scope
undici — . Attack surface: `SameSite` / `Strict` / `Lax` / `None`.
🔥 Severity
Severity: Low (CVSS 3.7/10). Risk of unauthorized operations or information disclosure
🔧 How to fix
Update to **8.5.0**.
🛡️ Workaround
Workaround: After parsing a `Set-Cookie` header, validate that the resulting `sameSite` attribute is one of `'Strict'`, `'Lax'`, or `'None'` (exact, case-insensitive) before forwarding or relying on it.
🔍 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

  1. 1
    Identify 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。

  2. 5
    Apply temporary workaround mitigate 
    After parsing a `Set-Cookie` header, validate that the resulting `sameSite` attribute is one of `'Strict'`, `'Lax'`, or `'None'` (exact, case-insensitive) before forwarding or relying on it.

    パッチが適用されるまでの応急処置として、After parsing a `Set-Cookie` header, validate that the resulting `sameSite` attribute is one of `'Strict'`, `'Lax'`, or `'None'` (exact, case-insensitive) before forwarding or relying on it. を実施。回避策の副作用 (機能低下) を確認した上で。

  3. 6
    Apply patch patch 
    Upgrade undici to 8.5.0

    ステージング環境で 8.5.0 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。

  4. 7
    Post-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":"8.5.0"}]}]

References

🍪 About cookies

We use cookies to keep you logged in, remember your language, and improve the service.

Details →