Medium severity · published May 20, 2026
CVE-2026-43620
Rsync < 3.4.3 Out-of-Bounds Array Read via recv_files()
5.5
CVSS
0.4%
EPSS
No
On KEV
Description
Rsync version 3.4.2 and prior contain a receiver-side out-of-bounds array read vulnerability in recv_files() in receiver.c that allows a malicious rsync server to crash the rsync client process. Attackers can exploit the vulnerability by setting CF_INC_RECURSE in compatibility flags and sending a specially crafted file list where the first sorted entry is not the leading dot directory, followed by a transfer record with ndx=0 and an iflag word without ITEM_TRANSFER, causing the receiver to read 8 bytes before the allocated pointer array and dereference an invalid pointer at an unmapped address, resulting in a deterministic SIGSEGV crash of the rsync client.
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
Attack vector
Local
Complexity
Low
Privileges
None
User interaction
Required
Confidentiality
None
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.4% · higher than 37% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
RS
rsync · RsyncProject
before 3.4.3 · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-43620
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-43620
Release Notes
https://github.com/RsyncProject/rsync/releases/tag/v3.4.3
Vendor Advisory
https://github.com/RsyncProject/rsync/security/advisories/GHSA-28pw-r563-rxvm
Third Party Advisory
https://www.vulncheck.com/advisories/rsync-out-of-bounds-array-read-via-recv-files
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