CVE-2026-53791

rsync < 3.5.0 Daemon IP Spoofing via PROXY Protocol Header

Published Aug 13, 2026 CVSS 4.0 · 9.1 Critical EPSS < 1% KEV · Not listed
Description
rsync daemon before 3.5.0 contains an IP address spoofing vulnerability that allows unauthenticated remote attackers to bypass IP-based access controls by sending a crafted PROXY protocol header with a forged source address. Attackers who can connect directly to the rsync daemon can inject a spoofed source IP in the PROXY protocol header to circumvent hosts allow/deny rules, gaining unauthorized access that would otherwise be blocked based on their real source address.

Remediation

No solution or workaround provided in the CVE record

Tracking

Sign in to view the affected projects.

Advisories

Source ID Title
Debian DLA Debian DLA DLA-4888-1 rsync security update
Debian DSA Debian DSA DSA-6527-1 rsync security update
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Samba
Samba rsync
CPEs cpe:2.3:a:samba:rsync:*:*:*:*:*:*:*:*
Vendors & Products Samba
Samba rsync
Type Values Removed Values Added
First Time appeared Rsync Project
Rsync Project rsync
Vendors & Products Rsync Project
Rsync Project rsync
Type Values Removed Values Added
Description rsync daemon before 3.5.0 contains an IP address spoofing vulnerability that allows unauthenticated remote attackers to bypass IP-based access controls by sending a crafted PROXY protocol header with a forged source address. Attackers who can connect directly to the rsync daemon can inject a spoofed source IP in the PROXY protocol header to circumvent hosts allow/deny rules, gaining unauthorized access that would otherwise be blocked based on their real source address.
Title rsync < 3.5.0 Daemon IP Spoofing via PROXY Protocol Header
Weaknesses CWE-290
References
Metrics cvssV3_1

{'score': 9.1, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N'}

cvssV4_0

{'score': 9.1, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
VulnCheck
Published
Updated
Aug 14, 2026, 6:09 PM
Reserved
Jun 10, 2026, 8:14 PM
Status
Analyzed
Published
Aug 13, 2026, 3:19 PM
Modified
Oct 24, 2026, 4:10 PM