TI-2026-31722 Aliases CVE-2026-43617 GHSA-4j4q-473w-9q2r

Rsync < 3.4.3 Authorization Bypass via Hostname Resolution

LOW 28CWE-289Published 2026-05-20 · Updated 2026-11-08

Key facts

Attack vector: Network
Privileges required: None
User interaction: None
Attack complexity: High
Attack requirements: Present
Impact type: —
Confidentiality · integrity · availability: Low · Low · None
Fix status: Partial Red Hat: 7 without a fix

Attack profile from CVSS 4.0 · CNA. Fix status from CNA and Red Hat.

Summary

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV

EPSS 0.00282 20th percentileScored 2026-11-07

Fix Partial rsync (RsyncProject): 3.4.3Red Hat: 7 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: None
Automatable: No
Technical impact: Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
Samba	rsync	before 3.4.3	3.4.3	Patch available	CNA

rsync VendorSamba Affected before 3.4.3 Fixed in 3.4.3 Patch available CNA

CPE configurations NVD · 1

CPE	Versions	Role	Vendor
cpe:2.3:a:samba:rsync::::::::	up to 3.4.2	Vulnerable	Samba

cpe:2.3:a:samba:rsync:*:*:*:*:*:*:*:* Versions up to 3.4.2 Vulnerable ·Samba

Remediation

Fix · CNA rsync (RsyncProject) Fixed in 3.4.3

Fixed in the same release

Records fixed by the same vendor advisory or release, as the CNA lists them.

Release · 2026-05-20
RsyncProject rsync 3.4.3
6 records Highest priority Priority LOW 6 LOW
Other records, highest priority first
- TI-2026-31724 Rsync < 3.4.3 Symlink Race Condition via Path-Based SyscallsPriority LOW 33
- TI-2026-23333 Rsync < 3.4.3 TOCTOU Race Condition Allows Symlink-Based Arbitrary File WritePriority LOW 33
- TI-2026-31725 Rsync < 3.4.3 Out-of-Bounds Array Read via recv_files()Priority LOW 31
Show all 6 records →

Vendor assessments

Red Hat

Red Hat rating: Moderate. Red Hat's page for this CVE →

Product	Status	Plan or fix
Red Hat Enterprise Linux 10	Affected	No fix planned: Out of support scope
Red Hat Enterprise Linux 6	Affected	No fix yet: Fix deferred
Red Hat Enterprise Linux 7	Affected	No fix yet: Fix deferred
Red Hat Enterprise Linux 8	Affected	No fix yet: Fix deferred
Red Hat Enterprise Linux 9	Affected	No fix yet: Fix deferred
Red Hat OpenShift AI (RHOAI)	Affected	—
Red Hat OpenShift Container Platform 4	Affected	No fix yet: Fix deferred

Timeline

2026-10-02 Threatist record created from CVE-2026-43617
2026-10-03 Alias added: GHSA-4j4q-473w-9q2r
2026-11-06 Affected versions changed · Red Hat

References

Advisory 1

GitHub Security Advisory (GHSA-rjfm-3w2m-jf4f)

Other 1

rsync 3.4.3 Release Notes

TI-2024-11208 Rsync: heap buffer overflow in rsync due to improper checksum length handling CVSS 3.1CRITICAL 9.8
TI-2024-11209 Rsync: info leak via uninitialized stack contents CVSS 3.1HIGH 7.5
TI-2024-11212 Rsync: --safe-links option bypass leads to path traversal CVSS 3.1HIGH 7.5
TI-2024-11211 Rsync: path traversal vulnerability in rsync CVSS 3.1HIGH 7.5
TI-2024-11210 Rsync: rsync server leaks arbitrary client files CVSS 3.1MEDIUM 6.8
TI-2017-12160 The receive_xattr function in xattrs.c in rsync 3.1.2 and 3.1.3-development does not… CVSS 3.1CRITICAL 9.8

See all 56 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences