CVE-2026-43620 Rsync < 3.4.3 Out-of-Bounds Array Read via recv_files()
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 4.0 detail
Vector CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:H/SC:N/SI:N/SA:NExploitable remotely over the network, without an account and if a user takes an action; an attacker can seriously compromise confidentiality, integrity or availability.
- Attack vector
- Network
- Attack complexity
- Low
- Attack requirements
- None
- Privileges required
- None
- Interaction
- Active
- Confidentiality
- None
- Integrity
- None
- Availability
- High
- Confidentiality of other systems
- None
- Integrity of other systems
- None
- Availability of other systems
- None
Affected products and versions
| Product | Affected versions | Fixed in |
|---|---|---|
| rsync 3.4 | earliest → < 3.4.3 | 3.4.3 |