EIPStackGroup OpENer 2.3.0 (commit 76b95cf) has an out-of-bounds read issue in Connection Manager handling of ForwardOpen requests when processing short malformed packets. An attacker can send a valid ENIP outer frame carrying a malformed CIP ForwardOpen/LargeForwardOpen request, causing the parser to continue reading fields even when request data is insufficient. This issue is remotely triggerable via network traffic and does not require authentication.
CVE-2026-51537
CRITICALPre-NVD 9.1Trending — 4 sources updated this weekElevated
9.1
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
- High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 0%CVSS: 9.1Exploit: NoneExposed: 0
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 9.1
- EG Score
- 0.0(none)
- EPSS
- 35.1%
- KEV
- Not listed
Published
July 13, 2026
Last Modified
July 15, 2026
Advisory Details (2)
Auto-updated Jul 14, 2026No patch confirmed yet.
generic
Stack Out-of-Bounds Read in ForwardOpen Parsing · Issue #564 · EIPStackGroup/OpENer · GitHub
https://github.com/EIPStackGroup/OpENer/issues/564Vendor Advisories for CVE-2026-51537(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 8× in last 7d / 8× 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.
- 2026-07-15 16:57 UTCEPSS rescore
- 2026-07-15 16:57 UTCEPSS rescore
- 2026-07-15 02:00 UTCEPSS rescore
- 2026-07-15 02:00 UTCEPSS rescore
- 2026-07-14 13:45 UTCMITRE cvelistV5CVSS v3 → 9.1 · severity → CRITICAL
- 2026-07-13 22:28 UTCNVD update
- 2026-07-13 21:44 UTCEG score recompute
- 2026-07-13 21:42 UTCMITRE cvelistV5first tracked
Related CVEs(same CWE)
Same CWE
10 shownCWE-125
- CVE-2014-2898EG 9.8CRITICAL
- CVE-2014-2897EG 9.8CRITICAL
- CVE-2014-2896EG 9.8CRITICAL
- CVE-2015-9290EG 9.8CRITICAL
- CVE-2016-10749EG 9.8CRITICAL
- CVE-1999-0006EG 9.8EPSS 96%CRITICAL
- CVE-2014-3180EG 9.1CRITICAL
- CVE-2014-1508EG 9.1EPSS 90%CRITICAL
- CVE-2016-5198NVD 8.8EG 9.0 KEVEPSS 98%HIGH
- CVE-2016-4523NVD 7.5EG 9.0 KEVEPSS 98%HIGH
Frequently asked(5)
What is CVE-2026-51537?
CVE-2026-51537 is a critical vulnerability published on July 13, 2026. EIPStackGroup OpENer 2.3.0 (commit 76b95cf) has an out-of-bounds read issue in Connection Manager handling of ForwardOpen requests when processing short malformed packets. An attacker can send a valid ENIP outer frame carrying a malformed CIP ForwardOpen/LargeForwardOpen request, causing the parser…
When was CVE-2026-51537 disclosed?
CVE-2026-51537 was first published in the National Vulnerability Database on July 13, 2026, with the most recent update on July 15, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-51537 actively exploited?
CVE-2026-51537 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 35.1% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-51537?
CVE-2026-51537 has a CVSS v3.1 base score of 9.1 (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-2026-51537?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-51537, 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-2026-51537
Is Your Infrastructure Affected by CVE-2026-51537?
EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.