In OCaml-TLS before 2.1.0, the client implementation does insufficient checks of the certificate provided by the server, which allows impersonation with certificates that are not meant for server authentication (because of KeyUsage and ExtendedKeyUsage).
CVE-2026-45388
CRITICALPre-NVD 9.19.1—Trending — 3 sources updated this weekElevated
EchelonGraph scoreHIGH confidence
Score 9.1 from GitHub Security Advisory (severity: CRITICAL) published 2026-06-15. 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
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
- 9.1(high)
- EPSS
- 13.1%
- KEV
- Not listed
Published
June 15, 2026
Last Modified
June 16, 2026
Advisory Details (1)
Auto-updated Jun 16, 2026No patch confirmed yet.
Vendor Advisories for CVE-2026-45388(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.
Frequently asked(5)
What is CVE-2026-45388?
CVE-2026-45388 is a critical vulnerability published on June 15, 2026. In OCaml-TLS before 2.1.0, the client implementation does insufficient checks of the certificate provided by the server, which allows impersonation with certificates that are not meant for server authentication (because of KeyUsage and ExtendedKeyUsage).
When was CVE-2026-45388 disclosed?
CVE-2026-45388 was first published in the National Vulnerability Database on June 15, 2026, with the most recent update on June 16, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-45388 actively exploited?
CVE-2026-45388 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 13.1% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-45388?
CVE-2026-45388 has a CVSS v3.1 base score of 9.1 (CISA-ADP / Vulnrichment enrichment; NVD's own analysis pending).
How do I remediate CVE-2026-45388?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-45388, 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-2026-45388
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