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CVE-2025-39866
high
CVSS 7.8
Use-After-Free in linux (CVE-2025-39866)
Summary
vulnerability in linux (CVE-2025-39866). Successful exploitation can lead to full system takeover.
AI summary snake-internal / snake-material-v2
A vulnerability tracked as **CVE-2025-39866** has been found in linux.
Successful exploitation can lead to full system takeover. CVSS score: 7.8/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "linux CVE-2025-39866" on the vendor's site.
CVE-2025-39866 (linux) — CWE-416 / CVSS v3 7.8
Attack vector: local / no user interaction
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
**use-after-free** (CWE-416) exists in linux.
📍 Affected scope
linux — .
🔥 Severity
Severity: High (CVSS 7.8/10). Successful exploitation can lead to full system takeover
🔧 How to fix
Update to the patched release per vendor advisory.
🛡️ 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 'linux' .` 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
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1Identify exposure identify
grep -r 'linux' . | 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 `linux` 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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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。
References
- web https://git.kernel.org/stable/c/1edc2feb9c759a9883dfe81cb5ed231412d8b2e4
- web https://git.kernel.org/stable/c/b187c976111960e6e54a6b1fff724f6e3d39406c
- web https://git.kernel.org/stable/c/bf89b1f87c72df79cf76203f71fbf8349cd5c9de
- web https://git.kernel.org/stable/c/c8c14adf80bd1a6e4a1d7ee9c2a816881c26d17a
- web https://git.kernel.org/stable/c/d02d2c98d25793902f65803ab853b592c7a96b29
- web https://git.kernel.org/stable/c/e2a14bbae5d8bacaa301362744a110e2be40a3a3
- web https://git.kernel.org/stable/c/e63052921f1b25a836feb1500b841bff7a4a0456
- web https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html
- web https://cert-portal.siemens.com/productcert/html/ssa-032379.html
- web https://cert-portal.siemens.com/productcert/html/ssa-082556.html
- web https://nvd.nist.gov/vuln/detail/CVE-2025-39866
- web https://github.com/advisories/GHSA-65ww-5pr7-752v