CVE-2026-45388 | BDVDB-2026-340423 Detail

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#

Per CVSS v3.1: confidentiality impact high, integrity impact high, availability impact none. Attack vector: network.

Weaknesses#

CWE-295 Improper Certificate Validation

References#

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

Exploit#

No public exploit known

History#

Version 12026-06-15Record published in the CVE List.
Version 22026-06-16Most recent update recorded in the CVE List.

Published

Published: 2026-06-15
Last modified: 2026-06-16

Vendor information

Vendor: Not stated
Product: Not stated

Score

9.1 Critical

EPSS

less than 1%, Very Low

Estimated chance of exploitation in the next 30 days. EPSS percentile: 13.2.

KEV

Not listed in the CISA Known Exploited Vulnerabilities catalog.

Impact

Not classified

Action

No specific action is recorded in the source data. Check the references for vendor guidance.

Affected Systems

No version data in the source record.

Scoring System

CVSS v4.0

Not available

CVSS v3.1

9.1 Critical

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

Metric breakdown
Attack Vector	Network
Attack Complexity	Low
Privileges Required	None
User Interaction	None
Scope	Unchanged
Confidentiality	High
Integrity	High
Availability	None

CVSS v3.0

Not available

CVSS v2

Not available

Source: CVE List v5 (record); CISA KEV (kev, action); FIRST EPSS (epss).