Off-by-one in Rsync - CVE-2026-45232

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Main Vulnerability Database Vulnerabilities #VU133149

Off-by-one in Rsync - CVE-2026-45232

Published: June 1, 2026


Vulnerability identifier: #VU133149
CSH Severity: Medium
CVSS v4: 6.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-45232
CWE-ID: CWE-193
Exploitation vector: Remote access
Exploit availability: No public exploit available

Vulnerability details

The vulnerability allows a remote attacker to cause a denial of service.

The vulnerability exists due to an off-by-one out-of-bounds stack write in establish_proxy_connection() in socket.c when processing the first response line from an HTTP CONNECT proxy. A remote attacker can return a pathological proxy response line without a newline terminator to cause a denial of service.

The issue is reachable only on the client side when RSYNC_PROXY is set, and the written byte is a fixed \0.


Affected software

Rsync
Gentoo Linux
Debian Linux
SUSE Linux Enterprise Server 15 SP5
SUSE Linux Enterprise Server 15 SP4
SUSE Linux Enterprise Server 12 SP5 LTSS Extended
SUSE Linux Enterprise Server 12 SP5
SUSE Linux Enterprise Server 15 SP6
SUSE Linux Enterprise High Performance Computing ESPOS 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 15
SUSE Linux Enterprise Server for SAP Applications 12
SUSE Linux Enterprise Server 12
SUSE Linux Enterprise High Performance Computing 12
SUSE Linux Enterprise Desktop 15
SUSE Linux Enterprise Real Time 15
SUSE Linux Enterprise Micro for Rancher
SUSE Linux Enterprise Micro
SUSE Linux Micro
Ubuntu
Basesystem Module
openSUSE Leap
openEuler
Anolis OS
Fedora
LANTIME Operating System Firmware (LTOS)
rsync (Ubuntu package)
rsync-debugsource
rsync-debuginfo
rsync
rsync-help
rsync (Debian package)
net-misc/rsync
rsync-doc
rsync-daemon

How to mitigate CVE-2026-45232

Install security update from vendor's website.

Rsync - update to 3.4.3
LANTIME Operating System Firmware (LTOS) - update to 7.10.012
rsync (Ubuntu package) - addressed in versions 3.1.0-2ubuntu0.4+esm3, 3.1.0-2ubuntu0.4+esm4, 3.1.1-3ubuntu1.3+esm5, 3.1.1-3ubuntu1.3+esm6, 3.1.2-2.1ubuntu1.6+esm3, 3.1.2-2.1ubuntu1.6+esm4, 3.1.3-8ubuntu0.9+esm1, 3.1.3-8ubuntu0.9+esm2, 3.2.7-0ubuntu0.22.04.6, 3.2.7-0ubuntu0.22.04.7, 3.2.7-1ubuntu1.4, 3.2.7-1ubuntu1.5, 3.4.1+ds1-7ubuntu0.2, 3.4.1+ds1-7ubuntu0.3, 3.4.1+ds1-5ubuntu1.2, 3.4.1+ds1-5ubuntu1.3
rsync-debugsource - addressed in versions 3.1.3-3.43.1, 3.2.3-150400.3.31.1, 3.2.7-7.1, 3.2.7-150600.3.21.1, 3.3.0-slfo.1.1_6.1
rsync-debuginfo - addressed in versions 3.1.3-3.43.1, 3.2.3-150400.3.31.1, 3.2.7-7.1, 3.2.7-150600.3.21.1, 3.3.0-slfo.1.1_6.1
rsync - addressed in versions 3.1.3-3.43.1, 3.2.3-150400.3.31.1, 3.2.7-7.1, 3.2.7-150600.3.21.1, 3.3.0-slfo.1.1_6.1
rsync - addressed in versions 3.1.3-14, 3.2.5-8, 3.2.7-10
rsync-debuginfo - addressed in versions 3.1.3-14, 3.2.5-8, 3.2.7-10
rsync-debugsource - addressed in versions 3.1.3-14, 3.2.5-8, 3.2.7-10
rsync-help - addressed in versions 3.1.3-14, 3.2.5-8, 3.2.7-10
rsync (Debian package) - addressed in versions 3.2.7-1+deb12u5, 3.4.1+ds1-5+deb13u3
net-misc/rsync - update to 3.4.3
rsync-doc - update to 3.4.3-1
rsync-daemon - update to 3.4.3-1
rsync - update to 3.4.3-1
rsync - addressed in versions 3.4.3-1.fc43, 3.4.3-1.fc44, 3.4.4-1.fc43

External References

Related Security Bulletins