CVE-2026-43620
published 2026-05-20CVE-2026-43620: 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…
PriorityP425medium5.5CVSS 3.1
AVLACLPRNUIRSUCNINAH
EPSS
0.50%
39.7th percentile
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.
Affected
4 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| rsyncproject | rsync | < 3.4.3 | 3.4.3 |
| samba | rsync | <= 3.4.2 | — |
| samba | rsync | — | — |
| ubuntu | rsync | — | — |
CVSS provenance
nvdv3.15.5MEDIUMCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
nvdv4.06.9MEDIUMCVSS:4.0/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
vendor_redhat6.9MEDIUM
vendor_ubuntu4.3MEDIUM
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Ubuntu
rsync regression
vendor_ubuntu·2026-06-16·CVSS 4.3
CVE-2025-10158 [MEDIUM] rsync regression
Title: rsync regression
Summary: USN-8349-1 introduced regressions in rsync.
USN-8349-1 fixed vulnerabilities in rsync. Unfortunately that update introduced multiple
regressions in rsync functionality. This update fixes the problem.
We apologize for the inconvenience.
Original advisory details:
Calum Hutton discovered that rsync contained a heap-based out-of-bounds
read when handling file transfers. A remote attacker with read access
to an rsync server could possibly use this issue to cause a denial of
service. (CVE-2025-10158)
Batuhan Sancak, Damien Neil, and Michael Stapelberg discovered that
rsync daemons configured without chroot protection were exposed to a
race condition on parent path components. A local attacker with write
access to a module could possibly use this issue to o
Ubuntu
rsync regression
vendor_ubuntu·2026-06-08·CVSS 4.3
CVE-2025-10158 [MEDIUM] rsync regression
Title: rsync regression
Summary: USN-8349-1 introduced regressions in rsync.
USN-8349-1 fixed vulnerabilities in rsync. The update introduced multiple
regressions in rsync functionality. This update fixes the problem.
Original advisory details:
Calum Hutton discovered that rsync contained a heap-based out-of-bounds
read when handling file transfers. A remote attacker with read access
to an rsync server could possibly use this issue to cause a denial of
service. (CVE-2025-10158)
Batuhan Sancak, Damien Neil, and Michael Stapelberg discovered that
rsync daemons configured without chroot protection were exposed to a
race condition on parent path components. A local attacker with write
access to a module could possibly use this issue to overwrite files,
obtain sensitive information, or esc
Ubuntu
rsync vulnerabilities
vendor_ubuntu·2026-06-01·CVSS 4.3
CVE-2026-43618 [MEDIUM] rsync vulnerabilities
Title: rsync vulnerabilities
Summary: Several security issues were fixed in rsync.
Calum Hutton discovered that rsync contained a heap-based out-of-bounds
read when handling file transfers. A remote attacker with read access
to an rsync server could possibly use this issue to cause a denial of
service. (CVE-2025-10158)
Batuhan Sancak, Damien Neil, and Michael Stapelberg discovered that
rsync daemons configured without chroot protection were exposed to a
race condition on parent path components. A local attacker with write
access to a module could possibly use this issue to overwrite files,
obtain sensitive information, or escalate privileges.
(CVE-2026-29518)
It was discovered that rsync did not properly validate a length value
while sorting extended attributes. An attacker could possi
Red Hat
rsync: rsync: Remote Denial of Service via Out-of-bounds Read
vendor_redhat·2026-05-20·CVSS 6.9
CVE-2026-43620 [MEDIUM] CWE-125 rsync: rsync: Remote Denial of Service via Out-of-bounds Read
rsync: rsync: Remote Denial of Service via Out-of-bounds Read
A flaw was found in rsync. A malicious rsync server can exploit an out-of-bounds read vulnerability in the `recv_files()` function. By manipulating compatibility flags and transfer records, the server can cause a connecting client to attempt to read memory outside of allocated bounds. This can lead to a segmentation fault, resulting in a denial of service for the client.
Statement: This Moderate impact flaw in rsync clients allows a remote, unauthenticated attacker to cause a denial-of-service by crafting a malicious rsync server. When a client pulls from such a server, an out-of-bounds read occurs due to an incomplete fix, leading to a deterministic crash. This affects any rsync client performing a normal pull from an attacke
Ubuntu
rsync vulnerabilities
vendor_ubuntu·2026-05-20·CVSS 4.3
CVE-2026-43620 [MEDIUM] rsync vulnerabilities
Title: rsync vulnerabilities
Summary: Several security issues were fixed in rsync.
Calum Hutton discovered that rsync contained a heap-based out-of-bounds
read when handling file transfers. A remote attacker with read access
to an rsync server could possibly use this issue to cause a denial of
service. This issue only affected Ubuntu 22.04 LTS, Ubuntu 24.04 LTS,
and Ubuntu 25.10. (CVE-2025-10158)
Batuhan Sancak, Damien Neil, and Michael Stapelberg discovered that
rsync daemons configured without chroot protection were exposed to a
race condition on parent path components. A local attacker with write
access to a module could possibly use this issue to overwrite files,
obtain sensitive information, or escalate privileges.
(CVE-2026-29518)
It was discovered that rsync did not properly val
VulDB
RsyncProject rsync up to 3.4.2 receiver.c recv_files out-of-bounds (GHSA-28pw-r563-rxvm / Nessus ID 315780)
vuldb·2026-06-02·CVSS 6.9
CVE-2026-43620 [MEDIUM] RsyncProject rsync up to 3.4.2 receiver.c recv_files out-of-bounds (GHSA-28pw-r563-rxvm / Nessus ID 315780)
A vulnerability has been found in RsyncProject rsync up to 3.4.2 and classified as problematic. Affected by this vulnerability is the function recv_files of the file receiver.c. Performing a manipulation results in out-of-bounds read.
This vulnerability is known as CVE-2026-43620. Remote exploitation of the attack is possible. No exploit is available.
The affected component should be upgraded.
GHSA
GHSA-jmf6-74r8-6c28: Rsync version 3
ghsa_unreviewed·2026-05-20
CVE-2026-43620 [MEDIUM] CWE-125 GHSA-jmf6-74r8-6c28: Rsync version 3
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.
No detection rules found.
No public exploits indexed.
2026-05-20
Published