6.9
MEDIUM CVSS 4.0
CVE-2026-43620
Rsync < 3.4.3 Out-of-Bounds Array Read via recv_files()
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.

INFO

Published Date :

May 20, 2026, 2:16 a.m.

Last Modified :

May 20, 2026, 2:16 a.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2026-43620 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

No affected product recoded yet

CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 3.1 MEDIUM 83251b91-4cc7-4094-a5c7-464a1b83ea10
CVSS 3.1 MEDIUM [email protected]
CVSS 4.0 MEDIUM 83251b91-4cc7-4094-a5c7-464a1b83ea10
CVSS 4.0 MEDIUM [email protected]
Solution
Update Rsync to a version that fixes the out-of-bounds read vulnerability in receiver.c.
  • Update Rsync to a patched version.
  • Verify the Rsync version is updated.
  • Monitor for client crashes during rsync transfers.
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2026-43620.

URL Resource
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
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-43620 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-43620 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-43620 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-43620 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • New CVE Received by [email protected]

    May. 20, 2026

    Action Type Old Value New Value
    Added 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.
    Added CVSS V4.0 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
    Added CVSS V3.1 AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
    Added CWE CWE-125
    Added Reference https://github.com/RsyncProject/rsync/releases/tag/v3.4.3
    Added Reference https://github.com/RsyncProject/rsync/security/advisories/GHSA-28pw-r563-rxvm
    Added Reference https://www.vulncheck.com/advisories/rsync-out-of-bounds-array-read-via-recv-files
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.