CVE-2026-43617

MEDIUM EPSS 19.9%
Published May 20, 20261mo ago · Modified Jun 17, 20261w ago
6.3 CVSS 4.0
Medium
Find Similar
Published May 20, 2026 1mo ago
Last Modified Jun 17, 2026 1w ago

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.

CVSS Details

Base Score
6.3
Exploitability
—
Impact
—
Vector string
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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Attack Vector Network
Attack Complexity High
Privileges Required None
User Interaction None
Scope X

Threat Intelligence

EPSS Exploit Probability
19.9% percentile
Exploit & Patch Status
No Known Exploit
No Patch Available

Weaknesses 1

CWE-289

Affected Products 1

VendorProductVersionRange
sambarsync* ≤3.4.2

References 3

  • github.com https://github.com/RsyncProject/rsync/releases/tag/v3.4.3
    Release Notes
  • github.com https://github.com/RsyncProject/rsync/security/advisories/GHSA-rjfm-3w2m-jf4f
    Vendor Advisory
  • vulncheck.com https://www.vulncheck.com/advisories/rsync-authorization-bypass-via-hostname-resolution
    Third Party Advisory

Remediation

No remediation data recorded yet

Check vendor advisories and the NVD entry for patch availability.