# CVE-2026-43617

## Summary

- **CVE ID:** CVE-2026-43617
- **Severity:** MEDIUM
- **CVSS Score:** 6.3 (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)
- **CWE:** CWE-289
- **Published:** May 20, 2026
- **Last Modified:** Jul 14, 2026

## 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.

## Affected Products

- RsyncProject — rsync (0)

## References

- [CNA](https://github.com/RsyncProject/rsync/security/advisories/GHSA-rjfm-3w2m-jf4f)
- [CNA](https://github.com/RsyncProject/rsync/releases/tag/v3.4.3)
- [CNA](https://www.vulncheck.com/advisories/rsync-authorization-bypass-via-hostname-resolution)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.28%
- **EPSS Percentile:** 20.5

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-10._