CVE-2026-70455
rsync 3.4.2 before 3.5.0 contains a denial of service vulnerability that allows a remote sender to exhaust system resources by specifying the --zt short alias for --compress-threads, which bypasses the refuse options directive's string matching on long option names. Attackers can specify --zt=N with a large value to spawn an unbounded number of Zstandard worker threads on the receiver, exhausting available thread and memory resources.
Published:Aug 13, 2026
Last Modified:Aug 14, 2026
EPS:Aug 13, 2026
EPSS Score:0.00479
CVSS Score:7.5
Affected Products
Vendor
Product
Action
Vendor
Rsync Project
Product
Rsync
Rsync Project
Rsync
Vendor
Samba
Product
Rsync
Samba
Rsync
Exploits
No exploit reference
Common Weakness Enumeration
Common Attack Pattern Enumeration and Classification (CAPEC)
Related CVEs
Common Vulnerability Scoring System
Attack Vector
Network
Adjacent
Local
Physical
Privileges Required
None
Low
High
User Interaction
None
Required
Scope
Unchanged
Changed
Confidentiality
None
Low
High
Integrity
None
Low
High
Availability
None
Low
High
