CVE-2026-70455 (GCVE-0-2026-70455)
Vulnerability from cvelistv5 – Published: 2026-08-13 14:45 – Updated: 2026-08-14 19:45
VLAI
EPSS
VEX
Title
rsync 3.4.2 < 3.5.0 DoS via --zt Zstandard Compression Thread Exhaustion
Summary
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.
Severity
SSVC
Exploitation: none
Automatable: yes
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-08-14 18:30 UTC
CWE
- CWE-770 - Allocation of Resources Without Limits or Throttling
Assigner
References
3 references
| URL | Tags |
|---|---|
| https://github.com/RsyncProject/rsync/security/ad… | vendor-advisory |
| https://github.com/RsyncProject/rsync/releases/ta… | release-notes |
| https://www.vulncheck.com/advisories/rsync-dos-vi… | third-party-advisory |
Impacted products
1 product
| Vendor | Product | Version | CPE status | |
|---|---|---|---|---|
| RsyncProject | rsync |
Affected:
3.4.2 , ≤ 3.4.4
(semver)
Unaffected: 3.5.0 (semver) cpe:2.3:a:samba:rsync:*:*:*:*:*:*:*:* |
Date Public
2026-08-12 00:00
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