Vulnerability in Samba (CVE-2026-43617)
Summary
Vulnerability in Samba (CVE-2026-43617). Risk of unauthorized operations or information disclosure.
Original description
The description as published by the source.
Rsync version 3.4.2 and prior contain an authorization bypass vulnerability in the rsync daemon's hostname-based access control list enforcement when configured with chroot. Attackers can bypass hostname-based deny rules by controlling the PTR record for their source IP address, allowing connections from hostnames that administrators intended to deny when reverse DNS resolution fails and defaults to UNKNOWN.
Source: NIST National Vulnerability Database NVD GitHub Advisory
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 CVE-2026-43617 has been found in Samba.
Risk of unauthorized operations or information disclosure. CVSS score: 4.8/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "Samba CVE-2026-43617" on the vendor's site.
CVE-2026-43617 (Samba) — CWE-289 / CVSS v3 4.8
Attack vector: remote (network-reachable) / unauthenticated / 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 (CWE-289) exists in Samba.
Check the vendor advisory for the affected versions of Samba.
Severity: Medium (CVSS 4.8/10). Risk of unauthorized operations or information disclosure.
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 '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
-
1Identify 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。 -
2Post-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。
Fix status by distribution
Fixed packages published by each distribution for this CVE
- Alpine Linux ALPINE-CVE-2026-43617 rsync Fixed in: 3.4.3-r0
- BellSoft Alpaquita BELL-CVE-2026-43617 rsync Fixed in: 3.4.3-r0
- Debian DEBIAN-CVE-2026-43617 rsync Fixed in: 3.2.3-4+deb11u4
- Ubuntu UBUNTU-CVE-2026-43617 rsync Fixed in: 3.1.0-2ubuntu0.4+esm3
References
- advisory disclosure@vulncheck.com
- patch disclosure@vulncheck.com
- web disclosure@vulncheck.com
- web nvd.nist.gov
- web github.com