CVE-2026-53791
rsync < 3.5.0 Daemon IP Spoofing via PROXY Protocol Header
- State
- Published
- Severity
- 9.1 Critical
- Published
- Aug 13, 2026
- Updated
- Aug 14, 2026
- Reserved
- Jun 10, 2026
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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 4.0 | 9.1 Critical | 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 | VulnCheck |
| 3.1 | 9.1 Critical | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N | VulnCheck |
Weaknesses
- CWE-290 Authentication Bypass by Spoofing
Affected Products
| Product | Versions |
|---|---|
rsyncRsyncProject |
|
References
- GitHub Security Advisory (GHSA-h2q9-5fr8-w635)vendor-advisory
- rsync 3.5.0 Release Notesrelease-notes
- https://www.vulncheck.com/advisories/rsync-daemon-ip-spoofing-via-proxy-protocol-headerthird-party-advisory
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