CVE-2026-51538

CRITICALPre-NVD 9.19.1—
EchelonGraph scoreHIGH confidence

Score 9.1 from GitHub Security Advisory (severity: CRITICAL) published 2026-07-14. CISA-ADP (Vulnrichment) CVSS v3.1 baseline 9.1; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: cisa-adp, epss, ghsa
Trending — 3 sources updated this weekElevated
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: Elevated riskExposed: 0

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

EIPStackGroup OpENer 2.3.0 (commit 76b95cf) suffers from an Incorrect Access Control vulnerability in its handling of encapsulation sessions. When the server processes critical encapsulation commands, it verifies whether the provided session_handle exists in the global session list, but it fails to verify whether that handle belongs to the specific TCP connection issuing the request. Because there is no strong binding between a session handle and its originating socket, any attacker on the network can use a valid session handle created by another legitimate client to bypass access controls.

CVSS v3
9.1
EG Score
9.1(high)
EG Risk
72(Attend)
EG Risk 72/100SSVC: Attend

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%
Exploitation40% × 40%
Automatability100% × 15%
Action: Remediate soon — notable exploitation risk.
EPSS PROB
0%
EPSS %ILE
31%
KEV
Not listed

Published

July 13, 2026

Last Modified

July 15, 2026

Advisory Details (2)

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

CVE-2026-51538 · GitHub

https://gist.github.com/MrAlaskan/8156ca3acd6754a9f66efede0a1351f2
generic

Incorrect Access Control on Session Handles · Issue #565 · EIPStackGroup/OpENer · GitHub

https://github.com/EIPStackGroup/OpENer/issues/565

Vendor Advisories for CVE-2026-51538(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 42× in last 7d / 64× 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. 2026-07-31 11:42 UTCGHSA enrichment
  2. 2026-07-31 07:28 UTCGHSA enrichment
  3. 2026-07-31 03:20 UTCGHSA enrichment
  4. 2026-07-30 23:13 UTCGHSA enrichment
  5. 2026-07-30 19:06 UTCEG score recompute
  6. 2026-07-30 19:05 UTCGHSA enrichment
  7. 2026-07-30 16:28 UTCEPSS rescore
  8. 2026-07-30 13:48 UTCGHSA enrichment
  9. 2026-07-30 09:38 UTCEG score recompute
  10. 2026-07-30 09:38 UTCGHSA enrichment
  11. 2026-07-30 05:30 UTCEG score recompute
  12. 2026-07-30 05:30 UTCGHSA enrichment
  13. 2026-07-30 01:30 UTCEPSS rescore
  14. 2026-07-30 01:15 UTCGHSA enrichment
  15. 2026-07-29 21:07 UTCGHSA enrichment
  16. 2026-07-29 15:10 UTCGHSA enrichment
  17. 2026-07-29 11:02 UTCGHSA enrichment
  18. 2026-07-29 06:55 UTCGHSA enrichment
  19. 2026-07-29 02:48 UTCGHSA enrichment
  20. 2026-07-28 22:40 UTCGHSA enrichment
  21. 2026-07-28 18:30 UTCEG score recompute
  22. 2026-07-28 18:30 UTCGHSA enrichment
  23. 2026-07-28 15:37 UTCEPSS rescore
  24. 2026-07-28 14:18 UTCGHSA enrichment
  25. 2026-07-28 10:08 UTCGHSA enrichment
Show 39 more
  1. 2026-07-28 06:01 UTCGHSA enrichment
  2. 2026-07-28 01:52 UTCGHSA enrichment
  3. 2026-07-27 21:45 UTCGHSA enrichment
  4. 2026-07-27 17:12 UTCEG score recompute
  5. 2026-07-27 17:12 UTCGHSA enrichment
  6. 2026-07-27 13:04 UTCGHSA enrichment
  7. 2026-07-27 08:45 UTCGHSA enrichment
  8. 2026-07-27 04:38 UTCGHSA enrichment
  9. 2026-07-27 00:30 UTCGHSA enrichment
  10. 2026-07-26 20:22 UTCGHSA enrichment
  11. 2026-07-26 16:13 UTCEG score recompute
  12. 2026-07-26 16:12 UTCGHSA enrichment
  13. 2026-07-26 14:54 UTCEPSS rescore
  14. 2026-07-26 12:00 UTCEG score recompute
  15. 2026-07-26 12:00 UTCGHSA enrichment
  16. 2026-07-25 14:18 UTCEPSS rescore
  17. 2026-07-24 14:18 UTCEPSS rescore
  18. 2026-07-23 14:18 UTCEPSS rescore
  19. 2026-07-23 03:19 UTCEG score recompute
  20. 2026-07-22 14:08 UTCEPSS rescore
  21. 2026-07-21 15:25 UTCEPSS rescore
  22. 2026-07-20 17:08 UTCEPSS rescore
  23. 2026-07-19 14:31 UTCEPSS rescore
  24. 2026-07-19 14:31 UTCEPSS rescore
  25. 2026-07-19 02:29 UTCEPSS rescore
  26. 2026-07-18 10:04 UTCEPSS rescore
  27. 2026-07-17 04:02 UTCGHSA enrichment
  28. 2026-07-16 23:55 UTCGHSA enrichment
  29. 2026-07-16 19:48 UTCEG score recompute▲ 9.10
  30. 2026-07-16 19:48 UTCGHSA enrichment
  31. 2026-07-16 17:03 UTCEPSS rescore
  32. 2026-07-15 16:57 UTCEPSS rescore
  33. 2026-07-15 16:57 UTCEPSS rescore
  34. 2026-07-15 02:00 UTCEPSS rescore
  35. 2026-07-15 02:00 UTCEPSS rescore
  36. 2026-07-14 13:45 UTCMITRE cvelistV5CVSS v3 → 9.1 · severity → CRITICAL
  37. 2026-07-13 22:28 UTCNVD update
  38. 2026-07-13 21:44 UTCEG score recompute
  39. 2026-07-13 21:42 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-51538?
CVE-2026-51538 is a critical vulnerability published on July 13, 2026. EIPStackGroup OpENer 2.3.0 (commit 76b95cf) suffers from an Incorrect Access Control vulnerability in its handling of encapsulation sessions. When the server processes critical encapsulation commands, it verifies whether the provided session_handle exists in the global session list, but it fails to…
When was CVE-2026-51538 disclosed?
CVE-2026-51538 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-2026-51538 actively exploited?
CVE-2026-51538 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 68.6% of all scored CVEs.
What is the CVSS score of CVE-2026-51538?
CVE-2026-51538 has a CVSS v3.1 base score of 9.1 (CISA-ADP / Vulnrichment enrichment; NVD's own analysis pending).
How do I remediate CVE-2026-51538?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-51538, 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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