Vulnerability in ntfs-3g (UBUNTU-CVE-2026-56136)

Summary

Vulnerability in ntfs-3g (UBUNTU-CVE-2026-56136). Confidential information can be exposed externally. Mitigation: upgrade to 1:2021.8.22-3ubuntu1.4 or later.

Original description

The description as published by the source.

In NTFS-3G through 2026.2.25, an out-of-bounds read exists in ntfs_ir_nill() in libntfs-3g/index.c that allows an attacker to read possibly confidential information in an ntfs-3g process by crafting a malicious NTFS image. This read operation is triggered by creation of a file with a crafted name.

Source: OSV.dev (Open Source Vulnerabilities) OSV

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-2026-56136 has been found in ntfs-3g.
Confidential information can be exposed externally.
What to do: upgrade ntfs-3g to 1:2021.8.22-3ubuntu1.4 or later.
If unsure, ask your IT team or search "ntfs-3g UBUNTU-CVE-2026-56136" on the vendor's site.

UBUNTU-CVE-2026-56136 (ntfs-3g)
Attack vector: local / no user interaction
Patched: 1:2021.8.22-3ubuntu1.4 — 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.

❓ What is the problem

A vulnerability (unclassified) exists in ntfs-3g.

📍 Affected scope

Check the vendor advisory for the affected versions of ntfs-3g.

🔥 Severity

Severity: ?. Confidential information can be exposed externally.

🔧 How to fix

Update to 1:2021.8.22-3ubuntu1.4.

🛡️ 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 'ntfs-3g' . 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 exposure identify
```
grep -r 'ntfs-3g' . | 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 ntfs-3g 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 patch patch
```
Upgrade ntfs-3g to 1:2021.8.22-3ubuntu1.4
```
ステージング環境で 1:2021.8.22-3ubuntu1.4 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 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。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。

Affected packages

Ubuntu:Pro:14.04:LTS ntfs-3g

[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]

Ubuntu:Pro:16.04:LTS ntfs-3g

[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]

Ubuntu:18.04:LTS ntfs-3g

[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]

Ubuntu:20.04:LTS ntfs-3g

[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}]

Ubuntu:22.04:LTS ntfs-3g

[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1:2021.8.22-3ubuntu1.4"}]}]

Ubuntu:24.04:LTS ntfs-3g

[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1:2022.10.3-1.2ubuntu3.2"}]}]

Ubuntu:26.04:LTS ntfs-3g

[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1:2022.10.3-5ubuntu1.1"}]}]

References

advisory ubuntu.com
report ubuntu.com
report cve.org