🔐 CVE Alert

CVE-2026-53791

CRITICAL 9.1

rsync < 3.5.0 Daemon IP Spoofing via PROXY Protocol Header

CVSS Score
9.1
EPSS Score
0.0%
EPSS Percentile
0th

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.

CWE CWE-290
Vendor rsyncproject
Product rsync
Published Aug 13, 2026
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CVSS v3 Breakdown

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
None

Affected Versions

RsyncProject / rsync
0 ≤ 3.4.4

References

NVD ↗ CVE.org ↗ EPSS Data ↗
github.com: https://github.com/RsyncProject/rsync/security/advisories/GHSA-h2q9-5fr8-w635 github.com: https://github.com/RsyncProject/rsync/releases/tag/v3.5.0 vulncheck.com: https://www.vulncheck.com/advisories/rsync-daemon-ip-spoofing-via-proxy-protocol-header