Rsync < 3.4.3 Authorization Bypass via Hostname Resolution_CVE-2026-43617

6.3 / 10

MEDIUM

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

Description

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.

Basic Information

ID CVE-2026-43617

Source VulnCheck

Published May 20, 2026 at 00:52

Affected Product

Vendor RsyncProject

Product rsync

Affected Versions RsyncProject rsync 0

CWE Classification

CWE-289

References

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    "published": "2026-05-20T00:52:38.965Z",
    "modified": "2026-05-20T00:52:38.965Z",
    "type": "cve",
    "title": "Rsync < 3.4.3 Authorization Bypass via Hostname Resolution",
    "source": "VulnCheck",
    "references": "https://github.com/RsyncProject/rsync/security/advisories/GHSA-rjfm-3w2m-jf4f\nhttps://github.com/RsyncProject/rsync/releases/tag/v3.4.3\nhttps://www.vulncheck.com/advisories/rsync-authorization-bypass-via-hostname-resolution",
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