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 Details
- CVSS 4.0 Base Score: 6.9 (MEDIUM)
- CVSS 4.0 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: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)
- CVSS 3.1 Base Score: 5.5
- CVSS 3.1 Vector: (CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H)
Covered by Rapid7
| Product | Vendor Advisory | Solution File | Added | Published |
|---|---|---|---|---|
| Alpine Linux | — | Upgrade rsync | May 25, 2026 | May 20, 2026 |
| Debian | — | Upgrade rsync | May 24, 2026 | May 24, 2026 |
| Freebsd | — | Upgrade rsync | Jun 15, 2026 | May 21, 2026 |
| Gentoo Linux | — | Upgrade net-misc/rsync. | Aug 16, 2026 | Aug 13, 2026 |
| Redhat_linux | — | No solution exists | Jul 17, 2026 | May 20, 2026 |
| Ubuntu | — | Upgrade rsyncUpgrade rsync (Ubuntu Pro) | May 25, 2026 | May 20, 2026 |
| Vmware Photon_os | — | Use 'tdnf update' to upgrade all packages to the latest version. | Jun 22, 2026 | May 20, 2026 |
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