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 UBUNTU-CVE-2026-78409 has been found in util-linux.
Successful exploitation can lead to full system takeover.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "util-linux UBUNTU-CVE-2026-78409" on the vendor's site.
UBUNTU-CVE-2026-78409 (util-linux)
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.
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 the patched release per vendor advisory.
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
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 | |
|---|---|---|
| Ubuntu:14.04:LTSutil-linux |
All versions→ Not listed |
Not listed |
| Ubuntu:Pro:16.04:LTSutil-linux |
All versions→ Not listed |
Not listed |
| Ubuntu:18.04:LTSutil-linux |
All versions→ Not listed |
Not listed |
| Ubuntu:Pro:20.04:LTSutil-linux |
All versions→ Not listed |
Not listed |
| Ubuntu:22.04:LTSutil-linux |
All versions→ Not listed |
Not listed |
| Ubuntu:24.04:LTSutil-linux |
All versions→ Not listed |
Not listed |
| Ubuntu:26.10util-linux |
All versions→ Not listed |
Not listed |
| Ubuntu:26.04:LTSutil-linux |
All versions→ Not listed |
Not listed |
This record does not list fixed versions. Check the article or the vendor advisory in the references for whether and where it is fixed.
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
- report ubuntu.com
- report cve.org
- report github.com
- report access.redhat.com
- report bugzilla.redhat.com