Improper access control in Rsync - CVE-2026-53786

Vulnerability identifier: #VU142293

CSH Severity: Medium

CVSS v4: 6.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-53786

CWE-ID: CWE-284

Exploitation vector: Remote access

Exploit availability: No public exploit available

The vulnerability allows a remote attacker to bypass file filtering restrictions and disclose sensitive information or modify data.

The vulnerability exists due to improper access control in the daemon filter check for client-supplied merge-file filters when processing a client-supplied merge-file filter via --remote-option. A remote attacker can supply a specially crafted merge-file filter path to bypass file filtering restrictions and disclose sensitive information or modify data.

The issue occurs because the merge-file filter was checked against a module-prefixed absolute path, causing daemon rules anchored at the module root to fail to match and allowing server-side merge-file rules from a forbidden file to be applied.

Rsync
Debian Linux
SUSE Linux Enterprise Server 15 SP6
SUSE Linux Enterprise Server 15 SP5
SUSE Linux Enterprise Server 15 SP4
SUSE Linux Enterprise Server for SAP Applications 15
SUSE Linux Enterprise Server 15
SUSE Linux Enterprise High Performance Computing 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
Basesystem Module
openSUSE Leap
openEuler
Fedora
rsync-debugsource
rsync-debuginfo
rsync
rsync-help
rsync (Debian 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-debugsource - update to 3.2.7-12
rsync-help - 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

• https://github.com/RsyncProject/rsync/security/advisories/GHSA-mrc3-6cwx-hch6

• 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
• openEuler 24.03 LTS SP4 update for rsync
• Debian update for rsync