Not Failing Securely ('Failing Open') in Rsync - CVE-2026-70452

Vulnerability identifier: #VU142266

CSH Severity: Medium

CVSS v4: 9.1 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-70452

CWE-ID: CWE-636

Exploitation vector: Remote access

Exploit availability: No public exploit available

The vulnerability allows a remote attacker to bypass host-based access restrictions and gain unauthorized access.

The vulnerability exists due to not failing securely in hosts deny access control processing when performing a forward DNS lookup of a configured hostname token. A remote attacker can connect from a host that should be denied to bypass host-based access restrictions and gain unauthorized access.

The issue occurs when forward lookup is enabled and a hostname token in hosts deny cannot be resolved, including during transient resolver failures or when a global daemon chroot lacks resolver configuration.

Rsync
Debian Linux
SUSE Linux Enterprise Server 15 SP6
SUSE Linux Enterprise Server 15 SP5
SUSE Linux Enterprise Server 15 SP4
SUSE Linux Enterprise High Performance Computing 15
SUSE Linux Enterprise Server for SAP Applications 15
SUSE Linux Enterprise Server 15
SUSE Linux Enterprise High Performance Computing LTSS 15
SUSE Linux Enterprise High Performance Computing ESPOS 15
SUSE Linux Enterprise Real Time 15
SUSE Linux Enterprise Desktop 15
SUSE Linux Enterprise Micro
SUSE Linux Enterprise Micro for Rancher
Red Hat Enterprise Linux for x86_64
Red Hat Enterprise Linux for IBM z Systems
Red Hat Enterprise Linux for Power, little endian
Red Hat Enterprise Linux for ARM 64
Basesystem Module
openSUSE Leap
openEuler
Fedora
rsync-debugsource
rsync-debuginfo
rsync
rsync-help
rsync (Debian package)
rsync (Red Hat package)

Install security update from vendor's website.

Rsync - update to 3.5.0
rsync-debugsource - addressed in versions 3.2.3-150400.3.34.1, 3.2.7-150600.3.24.1
rsync-debuginfo - addressed in versions 3.2.3-150400.3.34.1, 3.2.7-150600.3.24.1
rsync - addressed in versions 3.2.3-150400.3.34.1, 3.2.7-150600.3.24.1
rsync-help - update to 3.2.7-12
rsync-debugsource - update to 3.2.7-12
rsync-debuginfo - update to 3.2.7-12
rsync - update to 3.2.7-12
rsync (Debian package) - update to 3.5.0+ds1-0+deb13u1
rsync - addressed in versions 3.5.0-1.fc43, 3.5.0-1.fc44
rsync (Red Hat package) - update to 3.5.0-3.el10_2

• https://github.com/RsyncProject/rsync/security/advisories/GHSA-6692-28cx-wpqq

• Multiple vulnerabilities in Rsync
• SUSE update for rsync
• Fedora 44 update for rsync
• Fedora 43 update for rsync
• SUSE update for rsync
• openEuler 24.03 LTS SP3 update for rsync
• openEuler 24.03 LTS SP1 update for rsync
• Red Hat Enterprise Linux 10 update for rsync
• openEuler 24.03 LTS SP4 update for rsync
• Debian update for rsync