Rsync versionĀ 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.
History

Wed, 20 May 2026 16:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Wed, 20 May 2026 11:45:00 +0000

Type Values Removed Values Added
First Time appeared Rsync Project
Rsync Project rsync
Vendors & Products Rsync Project
Rsync Project rsync

Wed, 20 May 2026 01:30:00 +0000

Type Values Removed Values Added
Description Rsync versionĀ 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.
Title Rsync < 3.4.3 Authorization Bypass via Hostname Resolution
Weaknesses CWE-289
References
Metrics cvssV3_1

{'score': 4.8, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N'}

cvssV4_0

{'score': 6.3, 'vector': 'CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N'}


cve-icon MITRE

Status: PUBLISHED

Assigner: VulnCheck

Published: 2026-05-20T00:52:38.965Z

Updated: 2026-05-20T15:45:40.806Z

Reserved: 2026-05-01T18:22:45.639Z

Link: CVE-2026-43617

cve-icon Vulnrichment

Updated: 2026-05-20T13:25:04.043Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-05-20T02:16:36.233

Modified: 2026-05-20T13:58:07.923

Link: CVE-2026-43617

cve-icon Redhat

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