Description
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.
Affected products
samba: rsync
References3
- github.com/RsyncProject/rsync/security/advisories/GHSA-pg7g-xqm… Vendor Advisory
- github.com/RsyncProject/rsync/releases/tag/v3.5.0 ProductRelease Notes
- www.vulncheck.com/advisories/rsync-out-of-bounds-write-via-pars… Release NotesThird Party Advisory
Metrics
- CVSS 3.1
-
8.2
HIGH
Score source: NVD
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H - CVSS 4.0
-
8.3
HIGH
Score source: CNA
CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - EPSS — exploit probability
- 0% percentile: 32 · as of 12 November 2026
- CWE
- CWE-131CWE-787
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.