CVE-2026-70453
HighCVSS 7.5Exploitation Probability (EPSS)
Low risk42th percentile - higher than 42% of all known CVEs
Summary
Rsync before version 3.5.0 contains an algorithmic complexity vulnerability in the hash_search() function that allows a remote attacker to cause a denial of service by delivering a carefully constructed file list. A sender can exploit the quadratic-time worst-case behavior in hash lookups to exhaust receiver CPU resources with a modest number of crafted entries, causing a sustained denial of service.
Risk Assessment
An attacker can remotely overload the rsync server, causing service unavailability for legitimate users. This can lead to disruptions in critical data synchronization processes.
Recommendation
It is recommended to immediately upgrade rsync to version 3.5.0 or later, which includes the fix. If upgrading is not possible, restrict access to the rsync service to trusted clients only.
Original NVD description (English source)
rsync before 3.5.0 contains an algorithmic complexity vulnerability in the hash_search() function that allows a remote attacker to cause a denial of service by delivering a carefully constructed file list. A sender can exploit the quadratic-time worst-case behavior in hash lookups to exhaust receiver CPU resources with a modest number of crafted entries, causing a sustained denial of service.