CVE-2026-43620 Details
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.
A receiver-side out-of-bounds array read vulnerability has been identified in Rsync versions through 3.4.2. This vulnerability resides in the 'recv_files()' function of 'receiver.c' and allows a malicious Rsync server to crash the Rsync client process. Exploitation involves setting 'CF_INC_RECURSE' in the compatibility flags and sending a specially crafted file list. The first sorted entry must not be the leading dot directory, followed by a transfer record with 'ndx=0' and an 'iflag' word that excludes 'ITEM_TRANSFER'. This sequence causes the receiver to read 8 bytes before the allocated pointer array, dereference an invalid pointer at an unmapped address, and ultimately results in a deterministic 'SIGSEGV' crash of the Rsync client.
Users should upgrade to Rsync version 3.4.3, which includes the necessary patch. Until upgrading, Rsync clients can disable the 'inc_recursive' feature by using the '--no-inc-recursive' option or by only pulling from trusted Rsync hosts.
Metrics
CVSS 4.0 Severity and Vector Strings:
CVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
CISA-ADP
Assessed May 20, 2026References to Advisories, Solutions, and Tools
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| URL | Source(s) | Tag(s) |
|---|---|---|
| https://github.com/RsyncProject/rsync/releases/tag/v3.4.3 | [email protected] | Release Notes |
| https://github.com/RsyncProject/rsync/security/advisories/GHSA-28pw-r563-rxvm | [email protected] | Vendor Advisory |
| https://www.vulncheck.com/advisories/rsync-out-of-bounds-array-read-via-recv-files | [email protected] | Third Party Advisory |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-125 | Out-of-bounds Read | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| samba rsync | <= 3.4.2 |
CPE
Remediation
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Change History
6 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jul 24, 2026 | CVE Translated | [email protected] |
| Jul 14, 2026 | CVE Modified | [email protected] |
| Jun 17, 2026 | CVE Modified | [email protected] |
| Jun 17, 2026 | CVE Modified | CISA-ADP |
| May 21, 2026 | Initial Analysis | [email protected] |
| May 20, 2026 | New CVE Received | [email protected] |