Vulnerability in util-linux
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as ALPINE-CVE-2026-78409 has been found in util-linux.
Successful exploitation can lead to full system takeover.
What to do: upgrade util-linux to 2.42.3-r0 or later.
If unsure, ask your IT team or search "util-linux ALPINE-CVE-2026-78409" on the vendor's site.
ALPINE-CVE-2026-78409 (util-linux)
Attack vector: local / no user interaction
Patched: 2.42.3-r0 — 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.
A vulnerability (unclassified) exists in util-linux.
Check the vendor advisory for the affected versions of util-linux.
Severity: ?. Successful exploitation can lead to full system takeover.
Update to 2.42.3-r0.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'util-linux' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1
Identify exposureidentify
grep -r 'util-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
util-linuxを grep し、稼働しているサービス・バージョンを把握する。 -
2
Apply patchpatch
Upgrade util-linux to 2.42.3-r0ステージング環境で 2.42.3-r0 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を含めること。
-
3
Post-deployment verificationverify
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。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Affected packages
| Package | Affected → Fixed | |
|---|---|---|
| Alpine:v3.24util-linux |
< 2.42.3-r0→ 2.42.3-r0 |
2.42.3-r0 |
Original description The description as published by the source.
The X-mount.subdir option uses a detached-tree fast path on Linux 6.15 and later and passes the configured subdirectory to open_tree() with AT_SYMLINK_NOFOLLOW. That flag does not stop intermediate symlink traversal or keep resolution inside the newly mounted filesystem. A local unprivileged user with an fstab-authorized X-mount.subdir entry can attach a host path at the intended mountpoint.
Source: OSV.dev (Open Source Vulnerabilities) OSV
References
- advisory security.alpinelinux.org