CVE-2026-53791

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.

CVSS 4.0

9.1CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N

CVSS 3.1

9.1CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

EPSS

0.5% chance of exploitation in the next 30 days; higher than 42% of CVEs (scores of 2026-10-25)

CWE

CWE-290

Published

2026-08-13

Modified

2026-10-24

Record from

the NVD, synced 2026-10-24

Affected

• samba:rsync

References

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

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