CVE-2026-43617 — Rsync < 3.4.3 Authorization Bypass via Hostname Resolution
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. Att…
Published: 2026-05-20 · CVSS: 6.3 · CVSS 4.0
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: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7