Vulnerability in samba (UBUNTU-CVE-2026-1933)

Summary

Vulnerability in samba (UBUNTU-CVE-2026-1933). Risk of unauthorized operations or information disclosure. Mitigation: upgrade to 2:4.22.3+dfsg-4ubuntu2.4 or later.

Original description

The description as published by the source.

A flaw was found in Samba’s handling of NTFS-style reparse points on shares configured with read only = yes. Due to missing SMB-layer access checks, authenticated users with underlying filesystem write permissions may create or delete reparse point metadata through SMB operations even on read-only exports. This could allow modification of SMB-visible file behavior, including converting files into symbolic links or other reparse point types.

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-2026-1933 has been found in samba.
Risk of unauthorized operations or information disclosure.
What to do: upgrade samba to 2:4.22.3+dfsg-4ubuntu2.4 or later.
If unsure, ask your IT team or search "samba UBUNTU-CVE-2026-1933" on the vendor's site.

UBUNTU-CVE-2026-1933 (samba)
Attack vector: remote (network-reachable) / no user interaction
Patched: 2:4.22.3+dfsg-4ubuntu2.4 — 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 samba.

📍 Affected scope

Check the vendor advisory for the affected versions of samba.

🔥 Severity

Severity: ?. Risk of unauthorized operations or information disclosure.

🔧 How to fix

Update to 2:4.22.3+dfsg-4ubuntu2.4.

🛡️ 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 'samba' . 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 'samba' . | 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 samba 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 samba to 2:4.22.3+dfsg-4ubuntu2.4
```
ステージング環境で 2:4.22.3+dfsg-4ubuntu2.4 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:25.10 samba

[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2:4.22.3+dfsg-4ubuntu2.4"}]}]

Ubuntu:26.04:LTS samba

[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2:4.23.6+dfsg-1ubuntu2.1"}]}]

References

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