PT-2026-42054 · Rsync · Rsync

Pratham Gupta · Published 2026-05-20 · Updated 2026-05-24 · CVE-2026-43620

Positive Technologies (AI Summary)

CVSS v3.1

6.5

Medium

Base vector

AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H

Name of the Vulnerable Software and Affected Versions rsync versions prior to 3.4.3

Description A receiver-side out-of-bounds array read exists in the recv files() function within receiver.c. A malicious rsync server can trigger a deterministic SIGSEGV crash of the rsync client process 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. This sequence causes the receiver to read 8 bytes before the allocated pointer array and dereference an invalid pointer at an unmapped address.

Recommendations Update to version 3.4.3 or later.

Fix

Out of bounds Read

Weakness Enumeration

CWE-125

Related Identifiers

CVE-2026-43620

OPENSUSE-SU-2026:10857-1

USN-8283-1

Affected Products

Rsync

References · 24

• https://github.com/RsyncProject/rsync/security/advisories/GHSA-28pw-r563-rxvm · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2026-43620 · Security Note
• https://ubuntu.com/security/CVE-2026-43619 · Vendor Advisory
• https://ubuntu.com/security/CVE-2026-45232 · Vendor Advisory
• https://ubuntu.com/security/notices/USN-8283-1 · Vendor Advisory
• https://ubuntu.com/security/CVE-2025-10158 · Vendor Advisory
• https://osv.dev/vulnerability/USN-8283-1 · Vendor Advisory
• https://ubuntu.com/security/CVE-2026-29518 · Vendor Advisory
• https://ubuntu.com/security/CVE-2026-41035 · Vendor Advisory
• https://osv.dev/vulnerability/openSUSE-SU-2026:10857-1 · Vendor Advisory
• https://ubuntu.com/security/CVE-2026-43618 · Vendor Advisory
• https://cve.org/CVERecord?id=CVE-2026-43620 · Security Note
• https://ubuntu.com/security/CVE-2026-43617 · Vendor Advisory
• https://osv.dev/vulnerability/UBUNTU-CVE-2026-43620 · Vendor Advisory
• https://ubuntu.com/security/CVE-2026-43620 · Vendor Advisory