Allocation of Resources Without Limits or Throttling in Rsync - CVE-2026-70455

Vulnerability identifier: #VU142269

CSH Severity: Medium

CVSS v4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-70455

CWE-ID: CWE-770

Exploitation vector: Remote access

Exploit availability: No public exploit available

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

The vulnerability exists due to allocation of resources without limits or throttling in the rsync daemon sender when processing a PULL request with a large --compress-threads value. A remote attacker can send a request that names a large worker count to cause a denial of service.

A stock client is sufficient, and no crafted protocol is required. On anonymous modules, no authentication is required.

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
Fedora
rsync
rsync-debugsource
rsync-debuginfo
rsync (Debian package)
rsync (Red Hat package)

Install security update from vendor's website.

Rsync - update to 3.5.0
rsync - addressed in versions 3.2.3-150400.3.34.1, 3.2.7-150600.3.24.1
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 (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-rjvj-qgqg-cvx9

• Multiple vulnerabilities in Rsync
• SUSE update for rsync
• Fedora 44 update for rsync
• Fedora 43 update for rsync
• SUSE update for rsync
• Red Hat Enterprise Linux 10 update for rsync
• Debian update for rsync