CVE-2026-53791

CRITICALPre-NVD 9.19.1—
EchelonGraph scoreMEDIUM confidence

This critical-severity CVE scores 9.1 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.5%, top 61% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, secondary
9.1EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 9.1Exploit: None knownExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

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 v3
9.1
EG Score
9.1(medium)
EG Risk
41(Track)
EG Risk 41/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity91% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
39%
KEV
Not listed

Published

August 13, 2026

Last Modified

August 26, 2026

Advisory Details (3)

Auto-updated Aug 29, 2026
Patch available. Sources: github_release, github.
generic

rsync < 3.5.0 Daemon IP Spoofing via PROXY Protocol Header | Advisories | VulnCheck

https://www.vulncheck.com/advisories/rsync-daemon-ip-spoofing-via-proxy-protocol-header
github Patch Available

rsync: PROXY-protocol mode lets a direct client spoof the daemon's source address · Advisory · RsyncProject/rsync · GitHub

Affected: 3.5.0. (Precise introduced-in ranges being finalised.)

https://github.com/RsyncProject/rsync/security/advisories/GHSA-h2q9-5fr8-w635
github_release Patch Available

v3.5.0

Patch available: RsyncProject/rsync v3.5.0

https://github.com/RsyncProject/rsync/releases/tag/v3.5.0

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 12× in last 7d / 36× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-08-30 04:38 UTCEG score recompute
  2. 2026-08-30 01:22 UTCEPSS rescore
  3. 2026-08-29 07:41 UTCEG score recompute
  4. 2026-08-28 21:41 UTCEPSS rescore
  5. 2026-08-27 19:33 UTCEG score recompute
  6. 2026-08-27 14:25 UTCEPSS rescore
  7. 2026-08-26 16:27 UTCEG score recompute
  8. 2026-08-26 14:46 UTCEPSS rescore
  9. 2026-08-25 15:02 UTCEG score recompute
  10. 2026-08-25 13:49 UTCEPSS rescore
  11. 2026-08-24 14:29 UTCEG score recompute
  12. 2026-08-24 10:23 UTCEG score recompute
  13. 2026-08-23 01:22 UTCEG score recompute
  14. 2026-08-23 00:19 UTCEPSS rescore
  15. 2026-08-22 00:52 UTCEG score recompute
  16. 2026-08-21 23:49 UTCEPSS rescore
  17. 2026-08-21 00:21 UTCEG score recompute
  18. 2026-08-20 22:55 UTCEPSS rescore
  19. 2026-08-19 19:46 UTCEG score recompute
  20. 2026-08-19 17:04 UTCEPSS rescore
  21. 2026-08-18 15:03 UTCEG score recompute
  22. 2026-08-18 13:48 UTCEPSS rescore
  23. 2026-08-17 17:02 UTCEG score recompute
  24. 2026-08-17 13:47 UTCEPSS rescore
  25. 2026-08-16 16:31 UTCEG score recompute
Show 11 more
  1. 2026-08-16 14:56 UTCEPSS rescore
  2. 2026-08-16 04:17 UTCEG score recompute
  3. 2026-08-16 02:14 UTCEPSS rescore
  4. 2026-08-15 03:47 UTCEG score recompute
  5. 2026-08-15 01:30 UTCEPSS rescore
  6. 2026-08-14 19:36 UTCEG score recompute
  7. 2026-08-14 18:34 UTCEG score recompute
  8. 2026-08-14 13:14 UTCEG score recompute
  9. 2026-08-13 15:24 UTCEG score recompute
  10. 2026-08-13 15:12 UTCEG score recompute
  11. 2026-08-13 15:11 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-53791?
CVE-2026-53791 is a critical vulnerability published on August 13, 2026. 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…
When was CVE-2026-53791 disclosed?
CVE-2026-53791 was first published in the National Vulnerability Database on August 13, 2026, with the most recent update on August 26, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-53791 actively exploited?
CVE-2026-53791 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 61.2% of all scored CVEs.
What is the CVSS score of CVE-2026-53791?
CVE-2026-53791 has a CVSS v3 base score of 9.1 (NVD).
How do I remediate CVE-2026-53791?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-53791, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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