CVE-2026-45388

Severity CVSS v4.0:

Pending analysis

Type:

CWE-295 Improper Certificate Validation

Publication date:

15/06/2026

Last modified:

16/06/2026

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).

Impact

Vector 3.x

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N CVSS v3.1 Severity and Metrics:

Base Score: 9.10 CRITICAL
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

Attack Vector (AV): Network
Attack Complexity (AC): Low
Privileges Required (PR): None
User Interaction (UI): None
Scope (S): Unchanged
Confidentiality (C): High
Integrity (I): High
Availability (A): None

Base Score 3.x

9.10

Severity 3.x

CRITICAL

References to Advisories, Solutions, and Tools

https://osv.dev/vulnerability/OSEC-2026-06
https://osv.dev/vulnerability/OSEC-2026-06