Description
Rsync version 3.4.2 and prior contain an authorization bypass vulnerability in the rsync daemon's hostname-based access control list enforcement when configured with chroot. Attackers can bypass hostname-based deny rules by controlling the PTR record for their source IP address, allowing connections from hostnames that administrators intended to deny when reverse DNS resolution fails and defaults to UNKNOWN.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| RsyncProject | rsync | < 3.4.3 | 3.4.3 |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | rsync | 3.4.3+ds1-1 | — |
| Debian 13 | rsync | 3.4.1+ds1-5+deb13u3 | — |
| Debian 12 | rsync | 3.2.7-1+deb12u5 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.04 LTS | rsync | 3.4.1+ds1-7ubuntu0.2 | — |
| Ubuntu 25.10 | rsync | 3.4.1+ds1-5ubuntu1.2 | — |
| Ubuntu 24.04 LTS | rsync | 3.2.7-1ubuntu1.4 | — |
| Ubuntu 22.04 LTS | rsync | 3.2.7-0ubuntu0.22.04.6 | — |
Show 4 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 20.04 LTS | rsync | 3.1.3-8ubuntu0.9+esm1 | — |
| Ubuntu Pro 18.04 LTS | rsync | 3.1.2-2.1ubuntu1.6+esm3 | — |
| Ubuntu Pro 16.04 LTS | rsync | 3.1.1-3ubuntu1.3+esm5 | — |
| Ubuntu Pro 14.04 LTS | rsync | 3.1.0-2ubuntu0.4+esm3 | — |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 16.0 | rsync | 3.4.1-160000.4.1 | SUSE-SU-2026:23323-1, SUSE-SU-2026:22015-1 |
| SLES 16.0 | rsync | 3.4.1-160000.4.1 | SUSE-SU-2026:23323-1, SUSE-SU-2026:22015-1 |
| SLE Micro 6.2 | rsync | 3.4.1-160000.6.1 | SUSE-SU-2026:23289-1 |
Show 1 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLE Micro 6.0 | rsync | 3.2.7-8.1 | SUSE-SU-2026:23253-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | rsync | 3.4.3-1.1 | openSUSE-SU-2026:10857-1 |
| openSUSE Leap 16.0 | rsync | 3.4.1-160000.6.1 | openSUSE-SU-2026:21650-1 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.24 | rsync | 3.4.3-r0 | — |
| Alpine v3.23 | rsync | 3.4.3-r0 | — |
| Alpine v3.22 | rsync | 3.4.3-r0 | — |
| Alpine v3.21 | rsync | 3.4.3-r0 | — |
| Alpine v3.20 | rsync | 3.4.3-r0 | — |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2023 | rsync +1 | 3.5.1-1.amzn2023.0.1 | ALAS2023-2026-3131 |
Azure Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Azure Linux 3 | rsync | 3.4.3-1 | — |
Advisories 10
- WID-SEC-2026-2455 Oracle Solaris Drittanbieterkomponenten: Mehrere Schwachstellen BSI CERT-Bund (WID) · Nov 12, 2026
- WID-SEC-2026-2817 Rsync: Mehrere Schwachstellen BSI CERT-Bund (WID) · Nov 8, 2026
- WID-SEC-2026-1611 Rsync: Mehrere Schwachstellen BSI CERT-Bund (WID) · Oct 4, 2026
- ALAS2023-2026-3131 Important: rsync security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · Sep 28, 2026
- SUSE-SU-2026:23323-1 Security update for rsync SUSE / openSUSE Security Updates · Sep 10, 2026
- SUSE-SU-2026:23289-1 Security update for rsync SUSE / openSUSE Security Updates · Sep 4, 2026
- SUSE-SU-2026:23253-1 Security update for rsync SUSE / openSUSE Security Updates · Aug 27, 2026
- openSUSE-SU-2026:21650-1 Security update for rsync SUSE / openSUSE Security Updates · Aug 27, 2026
- SUSE-SU-2026:22015-1 Security update for rsync SUSE / openSUSE Security Updates · Jun 9, 2026
- openSUSE-SU-2026:10857-1 rsync-3.4.3-1.1 on GA media SUSE / openSUSE Security Updates · May 25, 2026
References
- GitHub Security Advisory (GHSA-rjfm-3w2m-jf4f) vendor-advisory
- rsync 3.4.3 Release Notes release-notes
- https://www.vulncheck.com/advisories/rsync-authorization-bypass-via-hostname-resolution third-party-advisory