Buffer overflow in Rsyncproject Rsync
CVE-2026-70457
rsync 3.2.3 before 3.5.0 contains an out-of-bounds write in parse_size_arg() where the return value of snprintf() is used directly as an index into a .bss-segment array without bounds checking. When snprintf truncates the formatted size string, the return value equals the number of characters that would have been written including the truncated portion, and this value may exceed the array length. The subsequent indexed write targets memory outside the intended array bounds, corrupting .bss memory.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:H.
EPSS exploit prediction
EPSS: 0.005 (42.0th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 42nd percentile — 42.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.004 · newest: 0.005 · change: +0.002
Affected products
- Rsyncproject Rsync — versions 3.2.3, 3.5.0
- Samba Rsync
Weakness classification (CWE)
References
- github.com/RsyncProject/rsync/releases/tag/v3.5.0 (release-notes, Product, Release Notes)
- github.com/RsyncProject/rsync/security/advisories/GHSA-pg7g-xqmr-xpfh (vendor-advisory, Vendor Advisory)
- www.vulncheck.com/advisories/rsync-out-of-bounds-write-via-parse-size-arg (Third Party Advisory, Release Notes, third-party-advisory)
Frequently asked questions
- What is CVE-2026-70457?
- CVE-2026-70457 is a medium-severity vulnerability in Rsyncproject Rsync, classified under Incorrect Calculation of Buffer Size. CVSS score: 6.5/10. Published 2026-08-13.
- How severe is CVE-2026-70457?
- Medium severity. CVSS v3 base score is 6.5 out of 10.