CVE-2026-70452

rsync 3.1.0 < 3.5.0 Access Control Bypass via DNS Resolution Failure

Published Aug 13, 2026 CVSS 4.0 · 9.1 Critical EPSS < 1% KEV · Not listed
Description
rsync 3.1.0 before 3.5.0 contains an access control bypass vulnerability that allows remote attackers to circumvent hosts deny rules by inducing DNS resolution failures during hostname-based access control evaluation. When a DNS lookup for a hostname-based deny rule fails, the daemon skips the rule rather than defaulting to a deny decision, enabling attackers who can trigger DNS failures to bypass module-level IP access controls and gain unauthorized access to restricted module file trees.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Debian DLA Debian DLA DLA-4888-1 rsync security update
Debian DSA Debian DSA DSA-6527-1 rsync security update
History
Type Values Removed Values Added
First Time appeared Samba
Samba rsync
CPEs cpe:2.3:a:samba:rsync:*:*:*:*:*:*:*:*
Vendors & Products Samba
Samba rsync
Type Values Removed Values Added
Metrics ssvc

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

Type Values Removed Values Added
First Time appeared Rsync Project
Rsync Project rsync
Vendors & Products Rsync Project
Rsync Project rsync
Type Values Removed Values Added
Description rsync 3.1.0 before 3.5.0 contains an access control bypass vulnerability that allows remote attackers to circumvent hosts deny rules by inducing DNS resolution failures during hostname-based access control evaluation. When a DNS lookup for a hostname-based deny rule fails, the daemon skips the rule rather than defaulting to a deny decision, enabling attackers who can trigger DNS failures to bypass module-level IP access controls and gain unauthorized access to restricted module file trees.
Title rsync 3.1.0 < 3.5.0 Access Control Bypass via DNS Resolution Failure
Weaknesses CWE-636
CWE-863
References
Metrics cvssV3_1

{'score': 7.4, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N'}

cvssV4_0

{'score': 9.1, 'vector': 'CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
VulnCheck
Published
Updated
Aug 14, 2026, 4:51 PM
Reserved
Aug 4, 2026, 2:52 PM
Status
Analyzed
Published
Aug 13, 2026, 3:19 PM
Modified
Nov 6, 2026, 3:59 PM