CVE-2026-45388

Published Jun 15, 2026 CVSS 3.1 · 9.1 Critical EPSS < 1% KEV · Not listed
Description
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).

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
References
History
Type Values Removed Values Added
Title OCaml‑TLS Insufficient Certificate Validation Enables Server Impersonation
Type Values Removed Values Added
Title OCaml‑TLS Insufficient Certificate Validation Enables Server Impersonation
Type Values Removed Values Added
Weaknesses CWE-295
Metrics cvssV3_1

{'score': 9.1, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N'}

ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'poc', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Ocaml
Ocaml ocaml
Vendors & Products Ocaml
Ocaml ocaml
Type Values Removed Values Added
Description 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).
References
Weaknesses

Sources

Status
PUBLISHED
Assigner
mitre
Published
Updated
Jun 16, 2026, 1:57 PM
Reserved
May 12, 2026, 12:00 AM
Status
Deferred
Published
Jun 15, 2026, 8:16 PM
Modified
Jun 17, 2026, 10:51 AM