rsync < 3.5.0 Daemon IP Spoofing via PROXY Protocol Header (RsyncProject rsync)

CVE-2026-53791
CRITICAL 9.1

At a glance

Source
NVD
EPSS
EPSS 0.50 % · percentile 43 ()
State
PUBLISHED
Published
Updated
Assigner
VulnCheck
NVD status
Analyzed

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.

Weaknesses (CWE)

  • CWE-290 — Authentication Bypass by Spoofing

References

Scores

VersionScoreVectorScored by
CVSS 4.0CRITICAL 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:NVulnCheck
CVSS 3.1CRITICAL 9.1CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:NVulnCheck
CVSS 4.0CRITICAL 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:XNVD · disclosure@vulncheck.com (Secondary)
CVSS 3.1CRITICAL 9.1CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:NNVD · disclosure@vulncheck.com (Secondary)

European references

Affected configurations (NVD CPE)

Affected products

ProductVersions
RsyncProject · rsyncaffected 0 ≤ 3.4.4 ; unaffected 3.5.0

Sources

SourceLicence
CVE List (CVEProject cvelistV5)CVE Program Terms of Use
EPSS (FIRST.org)FIRST — attribution requested
ENISA EUVDENISA — reproduction authorised, source acknowledged
NVD (NIST) via fkie-cad/nvd-json-data-feedsPublic domain — this product uses data from the NVD API but is not endorsed or certified by the NVD