CVE-2026-43620

Publication date 20 May 2026

Last updated 21 May 2026

Ubuntu priority

Cvss 3 Severity Score

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.

Status

Show unmaintained releases

Package	Ubuntu Release	Status
rsync	26.04 LTS resolute	Fixed 3.4.1+ds1-7ubuntu0.2
	25.10 questing	Fixed 3.4.1+ds1-5ubuntu1.2
	24.04 LTS noble	Fixed 3.2.7-1ubuntu1.4
	22.04 LTS jammy	Fixed 3.2.7-0ubuntu0.22.04.6
	20.04 LTS focal	Needs evaluation
	18.04 LTS bionic	Needs evaluation
	16.04 LTS xenial	Needs evaluation
	14.04 LTS trusty	Needs evaluation

Severity score breakdown

Parameter	Value
Base score	6.5 · Medium
Attack vector	Network
Attack complexity	Low
Privileges required	None
User interaction	Required
Scope	Unchanged
Confidentiality	None
Integrity impact	None
Availability impact	High
Vector	CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H

References

Related Ubuntu Security Notices (USN)

USN-8283-1
rsync vulnerabilities
20 May 2026