Description
rsync daemon 2.0.0 before 3.5.0 contains a denial of service vulnerability that allows unauthenticated remote attackers to exhaust daemon connection slots by stalling the handshake process before or after module selection without triggering the I/O timeout. Attackers can open many simultaneous connections and trickle data at the minimum rate to avoid timeout, or stall entirely before module selection where no timeout applies, consuming all available connection slots and denying service to legitimate clients.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| RsyncProject | rsync | 2.0.0 – ≤ 3.4.4 | 3.5.0 |
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 | 3.5.0+ds1-1 | — |
| Debian 13 | rsync | 3.5.0+ds1-0+deb13u1 | — |
| Debian 12 | rsync | 3.5.0+ds1-0+deb12u1 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | rsync | No fix yet | — |
| Ubuntu 26.04 LTS | rsync | No fix yet | — |
| Ubuntu 24.04 LTS | rsync | No fix yet | — |
| Ubuntu 22.04 LTS | rsync | No fix yet | — |
Show 4 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 20.04 LTS | rsync | No fix yet | — |
| Ubuntu Pro 18.04 LTS | rsync | No fix yet | — |
| Ubuntu Pro 16.04 LTS | rsync | No fix yet | — |
| Ubuntu Pro 14.04 LTS | rsync | No fix yet | — |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 10 | rsync +2 | 3.5.0-3.el10_2 | RHSA-2026:67463 |
| RHEL 9 | rsync +2 | 3.2.7-1.el9_8 | RHSA-2026:67462 |
| RHEL 8 | rsync +1 | 3.1.3-28.el8_10 | RHSA-2026:74095 |
AlmaLinux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux 10 | rsync +2 | 3.5.0-3.el10_2 | ALSA-2026:67463 |
| AlmaLinux 9 | rsync +2 | 3.2.7-1.el9_8 | ALSA-2026:67462 |
| AlmaLinux 8 | rsync +1 | 3.1.3-28.el8_10 | ALSA-2026:74095 |
Rocky Linux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Rocky Linux 10 | rsync | 3.5.0-3.el10_2 | RLSA-2026:67463 |
| Rocky Linux 9 | rsync | 3.2.7-1.el9_8 | RLSA-2026:67462 |
| Rocky Linux 8 | rsync | 3.1.3-28.el8_10 | RLSA-2026:74095 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP7 | rsync | 3.2.7-150600.3.24.1 | SUSE-SU-2026:3657-1 |
| SLES 15 SP6 | rsync | 3.2.7-150600.3.24.1 | SUSE-SU-2026:3657-1 |
| SLES 15 SP5 | rsync | 3.2.3-150400.3.34.1 | SUSE-SU-2026:3634-1 |
| SLES 15 SP4 | rsync | 3.2.3-150400.3.34.1 | SUSE-SU-2026:3634-1 |
Show 13 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 16.0 | rsync | 3.4.1-160000.6.1 | SUSE-SU-2026:23323-1 |
| SLES for SAP 15 SP6 | rsync | 3.2.7-150600.3.24.1 | SUSE-SU-2026:3657-1 |
| SLES for SAP 15 SP5 | rsync | 3.2.3-150400.3.34.1 | SUSE-SU-2026:3634-1 |
| SLES for SAP 15 SP4 | rsync | 3.2.3-150400.3.34.1 | SUSE-SU-2026:3634-1 |
| SLES 16.0 | rsync | 3.4.1-160000.6.1 | SUSE-SU-2026:23323-1 |
| SLE Micro 6.2 | rsync | 3.4.1-160000.6.1 | SUSE-SU-2026:23289-1 |
| SLE Micro 6.1 | rsync | 3.3.0-slfo.1.1_7.1 | SUSE-SU-2026:23254-1 |
| SLE Micro 6.0 | rsync | 3.2.7-8.1 | SUSE-SU-2026:23253-1 |
| SLE Micro 5.5 | rsync | 3.2.3-150400.3.34.1 | SUSE-SU-2026:3634-1 |
| SLE Micro 5.4 | rsync | 3.2.3-150400.3.34.1 | SUSE-SU-2026:3634-1 |
| SLE Micro 5.3 | rsync | 3.2.3-150400.3.34.1 | SUSE-SU-2026:3634-1 |
| SLE HPC 15 SP5 | rsync | 3.2.3-150400.3.34.1 | SUSE-SU-2026:3634-1 |
| SLE HPC 15 SP4 | rsync | 3.2.3-150400.3.34.1 | SUSE-SU-2026:3634-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | rsync | 3.5.1-1.1 | openSUSE-SU-2026:11869-1 |
| 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 | 3.5.0-r0 | — |
| Alpine v3.23 | rsync | 3.5.0-r0 | — |
| Alpine v3.22 | rsync | 3.5.0-r0 | — |
| Alpine v3.21 | rsync | 3.5.0-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 | 3.5.0-1 | — |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 8 | rsync +1 | 3.1.3-28.el8_10 | ELSA-2026-74095 |
Advisories 20
- WID-SEC-2026-2817 Rsync: Mehrere Schwachstellen BSI CERT-Bund (WID) · Nov 8, 2026
- ALSA-2026:67462 Important: rsync security, bug fix, and enhancement update AlmaLinux Security Advisories · Oct 29, 2026
- ALSA-2026:67463 Important: rsync security, bug fix, and enhancement update AlmaLinux Security Advisories · Oct 29, 2026
- ALSA-2026:74095 Important: rsync security, bug fix, and enhancement update AlmaLinux Security Advisories · Oct 29, 2026
- RHSA-2026:74095 Red Hat Security Advisory: rsync security, bug fix, and enhancement update Red Hat Security Advisories (RHSA) · Oct 10, 2026
- RHSA-2026:67463 Red Hat Security Advisory: rsync security, bug fix, and enhancement update Red Hat Security Advisories (RHSA) · Oct 10, 2026
- RHSA-2026:67462 Red Hat Security Advisory: rsync security, bug fix, and enhancement update Red Hat Security Advisories (RHSA) · Oct 10, 2026
- RLSA-2026:74095 Important: rsync security, bug fix, and enhancement update Rocky Linux Security Advisories · Oct 1, 2026
- ELSA-2026-74095 Important: rsync security, bug fix, and enhancement update (Oracle Linux 8) Oracle Linux Security Advisories (ELSA) · Oct 1, 2026
- ALAS2023-2026-3131 Important: rsync security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · Sep 28, 2026
- openSUSE-SU-2026:11869-1 rsync-3.5.1-1.1 on GA media SUSE / openSUSE Security Updates · Sep 24, 2026
- RLSA-2026:67462 Important: rsync security, bug fix, and enhancement update Rocky Linux Security Advisories · Sep 15, 2026
- RLSA-2026:67463 Important: rsync security, bug fix, and enhancement update Rocky Linux Security Advisories · Sep 15, 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-2026:23254-1 Security update for rsync SUSE / openSUSE Security Updates · Aug 31, 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-2026:3657-1 Security update for rsync SUSE / openSUSE Security Updates · Aug 21, 2026
- SUSE-SU-2026:3634-1 Security update for rsync SUSE / openSUSE Security Updates · Aug 18, 2026
References
- GitHub Security Advisory (GHSA-hrwq-ccf7-rw5m) vendor-advisory
- rsync 3.5.0 Release Notes release-notes
- https://www.vulncheck.com/advisories/rsync-connection-slot-exhaustion-dos-via-handshake-stall third-party-advisory