Out-of-bounds Read Affecting rsync package, versions <3.1.2-2.1ubuntu1.6+esm3


Severity

Recommended
0.0
medium
0
10

Based on Ubuntu security rating.

Threat Intelligence

EPSS
0.5% (39th percentile)

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  • Snyk IDSNYK-UBUNTU1804-RSYNC-16777202
  • published1 Jun 2026
  • disclosed20 May 2026

Introduced: 20 May 2026

NewCVE-2026-43620  (opens in a new tab)
CWE-125  (opens in a new tab)

How to fix?

Upgrade Ubuntu:18.04 rsync to version 3.1.2-2.1ubuntu1.6+esm3 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream rsync package and not the rsync package as distributed by Ubuntu. See How to fix? for Ubuntu:18.04 relevant fixed versions and status.

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 Base Scores

version 3.1