Inefficient Algorithmic Complexity in Rsync - CVE-2026-70453
Published: August 13, 2026
Vulnerability identifier: #VU142267
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-2026-70453
CWE-ID: CWE-407
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 inefficient algorithmic complexity in hash_search() when processing a crafted checksum set containing a long chain of equal weak checksums. A remote attacker can send a specially crafted checksum set to cause a denial of service.
Sustained CPU consumption can persist as shared host resource exhaustion rather than being limited to the attacker\'s own transfer.
Affected software
Rsync
How to mitigate CVE-2026-70453
Install security update from vendor's website.
Rsync - update to 3.5.0