** REJECT ** DO NOT USE THIS CANDIDATE NUMBER. ConsultIDs: CVE-2026-43617. Reason: This candidate is a duplicate of CVE-2026-43617. Notes: All CVE users should reference CVE-2026-43617 instead of this candidate.

No CVSS v4.0

No CVSS v3.1

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

The EPSS score is 0.00146.

Key SSVC decision points have not yet been added.

No data.

No data.

No data.

Project Subscriptions

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Advisories

No advisories yet.

Fixes

Solution

No solution given by the vendor.

Workaround

No workaround given by the vendor.

References

No reference.

History

Tue, 21 Jul 2026 17:30:00 +0000

Type Values Removed Values Added
Title Rsync: hostname/ACL bypass on DNS-lookup failure

Tue, 21 Jul 2026 16:30:00 +0000

Type Values Removed Values Added
Title Rsync: hostname/ACL bypass on DNS-lookup failure
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Tue, 21 Jul 2026 15:30:00 +0000

Type Values Removed Values Added
Description Rsync is a file-copying tool that uses a delta-transfer algorithm to synchronize remote and local files. In versions prior to 3.4.3, when using a daemon configured with a chroot, the reverse DNS lookup of the connecting client was performed after the chroot had been entered. If the chroot did not contain the files glibc needs for resolution (/etc/resolv.conf, /etc/nsswitch.conf, /etc/hosts, NSS service modules), the lookup failed and the connecting hostname was set to "UNKNOWN". Hostname-based deny rules ("hosts deny = *.evil.example") therefore could not match, and an attacker who controlled the PTR record for their source IP could connect from a hostname that the administrator had intended to deny. IP-based ACLs ("hosts allow = 10.0.0.0/8") are unaffected. This issue is fixed in version 3.4.3. ** REJECT ** DO NOT USE THIS CANDIDATE NUMBER. ConsultIDs: CVE-2026-43617. Reason: This candidate is a duplicate of CVE-2026-43617. Notes: All CVE users should reference CVE-2026-43617 instead of this candidate.
Weaknesses CWE-863
References
Metrics cvssV3_1

{'score': 4.8, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N'}

Tue, 21 Jul 2026 14:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Mon, 20 Jul 2026 21:00:00 +0000

Type Values Removed Values Added
Description Rsync is a file-copying tool that uses a delta-transfer algorithm to synchronize remote and local files. In versions prior to 3.4.3, when using a daemon configured with a chroot, the reverse DNS lookup of the connecting client was performed after the chroot had been entered. If the chroot did not contain the files glibc needs for resolution (/etc/resolv.conf, /etc/nsswitch.conf, /etc/hosts, NSS service modules), the lookup failed and the connecting hostname was set to "UNKNOWN". Hostname-based deny rules ("hosts deny = *.evil.example") therefore could not match, and an attacker who controlled the PTR record for their source IP could connect from a hostname that the administrator had intended to deny. IP-based ACLs ("hosts allow = 10.0.0.0/8") are unaffected. This issue is fixed in version 3.4.3.
Title Rsync: hostname/ACL bypass on DNS-lookup failure
Weaknesses CWE-863
References
Metrics cvssV3_1

{'score': 4.8, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N'}

Projects

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cve-icon MITRE

Status: REJECTED

Assigner: GitHub_M

Published:

Updated: 2026-07-21T15:09:28.320Z

Reserved: 2026-05-06T18:28:20.886Z

Link: CVE-2026-44507

cve-icon Vulnrichment

Updated: 2026-07-21T12:50:47.912Z

cve-icon NVD

No data.

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses

No weakness.