Is CVE-2026-43617 in the CISA KEV catalog?

No. CVE-2026-43617 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2026-43617?

CVE-2026-43617 has a CVSS v3 base score of 4.8 (Moderate).

What is the EPSS score for CVE-2026-43617?

CVE-2026-43617 has an EPSS score of 0.28% (20th percentile), estimating the probability of exploitation in the next 30 days.

How do I fix CVE-2026-43617?

Upgrade rsync on debian 11 to 3.2.3-4+deb11u4 or later. Fixes are available for 2 affected products.

CVE & CISA-KEV Catalog

CVE-2026-43617

MEDIUM

4.8

CVSS v3

NVD

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.

CWE-289

How to fix

Remediation Available

rsyncDebian

Fixed in:3.2.3-4+deb11u4CVE-2026-43617

Fixed in:3.2.7-1+deb12u5CVE-2026-43617

Fixed in:3.4.1+ds1-5+deb13u3CVE-2026-43617

Fixed in:3.4.3+ds1-1CVE-2026-43617

rsyncUbuntu

Fixed in:3.1.0-2ubuntu0.4+esm3USN-8349-1

Fixed in:3.1.1-3ubuntu1.3+esm5USN-8349-1

Fixed in:3.1.2-2.1ubuntu1.6+esm3USN-8349-1

Fixed in:3.1.3-8ubuntu0.9+esm1USN-8349-1

Fixed in:3.2.7-0ubuntu0.22.04.6USN-8283-1

Fixed in:3.2.7-1ubuntu1.4USN-8283-1

Fixed in:3.4.1+ds1-5ubuntu1.2USN-8283-1

Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.

CVSS v3 Vector

Exploitability

Attack VectorNetwork

Attack ComplexityHigh

Privileges RequiredNone

User InteractionNone

ScopeUnchanged

Impact

ConfidentialityLow

IntegrityLow

AvailabilityNone

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N

Exploit Intelligence

0.28%probability of exploitation in 30 days

20thpercentile

Low risk: more likely to be exploited than 20% of all known CVEs.

References

Vendor Advisory1

github.com

Third-Party Advisory1

vulncheck.com

Release Notes1

github.com

Embed a live status badge for CVE-2026-43617

Markdown

[![CVE-2026-43617](https://tridentstack.com/cve/badge/CVE-2026-43617.svg)](https://tridentstack.com/cve/CVE-2026-43617)

HTML

<a href="https://tridentstack.com/cve/CVE-2026-43617"><img src="https://tridentstack.com/cve/badge/CVE-2026-43617.svg" alt="CVE-2026-43617"></a>

Find and fix vulnerabilities across your fleet

TridentStack Control continuously scans your Windows, macOS, and Linux fleet for known vulnerabilities, prioritizes them by severity and active exploitation, and patches them automatically.

Start free

This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-05-21.