CVE-2026-43620

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

References

• https://github.com/RsyncProject/rsync/releases/tag/v3.4.3
• https://github.com/RsyncProject/rsync/security/advisories/GHSA-28pw-r563-rxvm
• https://www.vulncheck.com/advisories/rsync-out-of-bounds-array-read-via-recv-files