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CVE-2025-21726
high
CVSS 7.8
Use-After-Free in linux (CVE-2025-21726)
Summary
vulnerability in linux (CVE-2025-21726). Successful exploitation can lead to full system takeover.
AI summary snake-internal / snake-material-v2
A vulnerability tracked as **CVE-2025-21726** 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-2025-21726" on the vendor's site.
CVE-2025-21726 (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
-
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/4c6209efea2208597dbd3e52dc87a0d1a8f2dbe1
- web https://git.kernel.org/stable/c/6f45ef616775b0ce7889b0f6077fc8d681ab30bc
- web https://git.kernel.org/stable/c/7000507bb0d2ceb545c0a690e0c707c897d102c2
- web https://git.kernel.org/stable/c/8ca38d0ca8c3d30dd18d311f1a7ec5cb56972cac
- web https://git.kernel.org/stable/c/a54091c24220a4cd847d5b4f36d678edacddbaf0
- web https://git.kernel.org/stable/c/dd7d37ccf6b11f3d95e797ebe4e9e886d0332600
- web https://git.kernel.org/stable/c/f4f1b1169fc3694f9bc3e28c6c68dbbf4cc744c0
- web https://lists.debian.org/debian-lts-announce/2025/03/msg00028.html
- web https://lists.debian.org/debian-lts-announce/2025/05/msg00030.html
- web https://cert-portal.siemens.com/productcert/html/ssa-265688.html
- web https://nvd.nist.gov/vuln/detail/CVE-2025-21726
- web https://github.com/advisories/GHSA-4gxw-5w55-6f5h