Vulnerability in Rsyncproject Rsync
CVE-2026-70453
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.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
EPSS exploit prediction
EPSS: 0.007 (53.1th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 53rd percentile — 53.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.005 · newest: 0.007 · change: +0.002
Affected products
- Rsyncproject Rsync — versions 0, 3.5.0
Weakness classification (CWE)
References
- github.com/RsyncProject/rsync/releases/tag/v3.5.0 (release-notes)
- github.com/RsyncProject/rsync/security/advisories/GHSA-8x5r-mjx8-83hv (vendor-advisory)
- www.vulncheck.com/advisories/rsync-algorithmic-complexity-dos-via-hash-search (third-party-advisory)
Frequently asked questions
- What is CVE-2026-70453?
- CVE-2026-70453 is a high-severity vulnerability in Rsyncproject Rsync, classified under Inefficient Algorithmic Complexity. CVSS score: 7.5/10. Published 2026-08-13.
- How severe is CVE-2026-70453?
- High severity. CVSS v3 base score is 7.5 out of 10.