Sign in Sign up
JA · EN · FR
SecPulse
← Back
CVE-2026-21441 high CVSS 7.5

Vulnerability in urllib3 (CVE-2026-21441)

Summary

vulnerability in urllib3 (CVE-2026-21441). Risk of unauthorized operations or information disclosure. Exploitable via ``gzip``.

AI summary snake-internal / snake-material-v2

A vulnerability tracked as **CVE-2026-21441** has been found in urllib3. Attackers can target a specific entry point like ``gzip`` over the network to misuse the product. Risk of unauthorized operations or information disclosure. CVSS score: 7.5/10. What to do: apply the vendor's official patched release. If unsure, ask your IT team or search "urllib3 CVE-2026-21441" on the vendor's site.
CVE-2026-21441 (urllib3) — CWE-409 / CVSS v3 7.5 Attack vector: remote (network-reachable) / unauthenticated / no user interaction Attack surface: `gzip` / `deflate` / `zstd` Workaround: disable redirects by setting `redirect=False` for requests to untrusted source. 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-409) exists in urllib3. Attackers reach the vulnerable code path via ``gzip`` without authentication.
📍 Affected scope
urllib3 — . Attack surface: `gzip` / `deflate` / `zstd`.
🔥 Severity
Severity: High (CVSS 7.5/10). Risk of unauthorized operations or information disclosure
🔧 How to fix
Update to the patched release per vendor advisory.
🛡️ Workaround
Workaround: disable redirects by setting `redirect=False` for requests to untrusted source.
🔍 Detection
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run `grep -r 'urllib3' .` 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 'urllib3' . | 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 `urllib3` 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 
    disable redirects by setting `redirect=False` for requests to untrusted source.

    パッチが適用されるまでの応急処置として、disable redirects by setting `redirect=False` for requests to untrusted source. を実施。回避策の副作用 (機能低下) を確認した上で。

  3. 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。

References

🍪 About cookies

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

Details →