CVE-2026-51539

HIGHPre-NVD 7.5Trending — 3 sources updated this week
7.5
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: —CVSS: 7.5Exploit: NoneExposed: 0

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

A Denial of Service (DoS) vulnerability exists in the receive loop of libmodbus 3.1.12 when running on Windows. The issue stems from improper timeout management during network read operations.

CVSS v3
7.5
EG Score
0.0(none)
EPSS
—
KEV
Not listed

Published

July 13, 2026

Last Modified

July 14, 2026

Advisory Details (2)

Auto-updated Jul 14, 2026
No patch confirmed yet.
generic

CVE-2026-51539 · GitHub

https://gist.github.com/MrAlaskan/f22dcf01a5dd90da1b191fcee9043a32
generic

Slowloris-Style DoS in Modbus TCP Receive Path on Windows · Issue #843 · stephane/libmodbus · GitHub

https://github.com/stephane/libmodbus/issues/843

Vendor Advisories for CVE-2026-51539(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 4× in last 7d / 4× 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. 2026-07-14 13:45 UTCMITRE cvelistV5CVSS v3 → 7.5 · severity → HIGH
  2. 2026-07-13 22:28 UTCNVD update
  3. 2026-07-13 21:44 UTCEG score recompute
  4. 2026-07-13 21:42 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(4)

What is CVE-2026-51539?
CVE-2026-51539 is a high vulnerability published on July 13, 2026. A Denial of Service (DoS) vulnerability exists in the receive loop of libmodbus 3.1.12 when running on Windows. The issue stems from improper timeout management during network read operations.
When was CVE-2026-51539 disclosed?
CVE-2026-51539 was first published in the National Vulnerability Database on July 13, 2026, with the most recent update on July 14, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
What is the CVSS score of CVE-2026-51539?
CVE-2026-51539 has a CVSS v3.1 base score of 7.5 (CISA-ADP / Vulnrichment enrichment; NVD's own analysis pending). EchelonGraph synthesises NVD + CISA KEV + FIRST EPSS + GHSA into a combined EG score of 0.0.
How do I remediate CVE-2026-51539?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-51539, 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

Explore the affected products and dependency analysis for CVE-2026-51539

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