CVE-2026-45389

Published Jun 15, 2026 CVSS 3.1 · 7.4 High EPSS < 1% KEV · Not listed
Description
In OCaml-TLS before 2.1.0, the server implementation does insufficient checks of the certificate provided by the client (when doing client authentication), which allows impersonation with certificates that are not meant for client 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 Insufficient Client Certificate Validation in OCaml‑TLS Enables Client Impersonation
Weaknesses CWE-20 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'}

cvssV3_1

{'score': 7.4, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N'}

ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
Title Insufficient Client Certificate Validation in OCaml‑TLS Enables Client Impersonation
Weaknesses CWE-20
Type Values Removed Values Added
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 server implementation does insufficient checks of the certificate provided by the client (when doing client authentication), which allows impersonation with certificates that are not meant for client authentication (because of KeyUsage and ExtendedKeyUsage).
References
Weaknesses

Sources

Status
PUBLISHED
Assigner
mitre
Published
Updated
Jun 17, 2026, 3:52 PM
Reserved
May 12, 2026, 12:00 AM
Status
Deferred
Published
Jun 15, 2026, 8:16 PM
Modified
Jun 17, 2026, 5:17 PM