Description
** 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.
Published: 2026-07-20
Score: n/a
EPSS: < 1% Very Low
KEV: No
Impact: n/a
Action: n/a
AI Analysis

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Remediation

No vendor fix or workaround currently provided.

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Tracking

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Advisories

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References

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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'}

Subscriptions

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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

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cve-icon OpenCVE Enrichment

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Weaknesses

No weakness.