Is CVE-2026-53791 being exploited?

No public exploit is currently tracked.

How severe is CVE-2026-53791?

CVE-2026-53791 has a CVSS v3 severity of CRITICAL (9.1).

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CVE-2026-53791

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.