Out-of-bounds write in Rsync - CVE-2026-70456
Published: August 13, 2026
Vulnerability identifier: #VU142270
CSH Severity: High
CVSS v4: 8.8 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-70456
CWE-ID: CWE-787
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to cause a denial of service or modify memory.
The vulnerability exists due to out-of-bounds write in read_args() when processing daemon client arguments that make glob expansion land the argument count exactly on maxargs. A remote attacker can send a specially crafted request to cause a denial of service or modify memory.
The write occurs when a trailing NULL pointer is written one pointer past the end of the heap allocation.
Affected software
Rsync
How to mitigate CVE-2026-70456
Install security update from vendor's website.
Rsync - update to 3.5.0