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 21, 2026, 8:47 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| 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 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 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 | Release Notes |
| https://github.com/RsyncProject/rsync/security/advisories/GHSA-28pw-r563-rxvm | Vendor Advisory |
| https://www.vulncheck.com/advisories/rsync-out-of-bounds-array-read-via-recv-files | Third Party Advisory |
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.
-
Initial Analysis by [email protected]
May. 21, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H Added CPE Configuration OR *cpe:2.3:a:samba:rsync:*:*:*:*:*:*:*:* versions up to (including) 3.4.2 Added Reference Type VulnCheck: https://github.com/RsyncProject/rsync/releases/tag/v3.4.3 Types: Release Notes Added Reference Type VulnCheck: https://github.com/RsyncProject/rsync/security/advisories/GHSA-28pw-r563-rxvm Types: Vendor Advisory Added Reference Type VulnCheck: https://www.vulncheck.com/advisories/rsync-out-of-bounds-array-read-via-recv-files Types: Third Party Advisory -
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