CVE-2026-45389 Details
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).
A vulnerability exists in OCaml-TLS versions prior to 2.1.0, where the server implementation fails to properly validate client certificates during authentication. This oversight allows impersonation using certificates not intended for client authentication, as specified by their KeyUsage and ExtendedKeyUsage extensions. The issue arises when mutual TLS (mTLS) is enabled, and the server accepts certificates that should not be authorized for client identity.
Users can upgrade to OCaml-TLS version 2.1.0 or later, where this vulnerability has been addressed.
Metrics
CVSS 4.0 Severity and Vector Strings:
VolerionCVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
Volerion
Assessed Jun 15, 2026CISA-ADP
Assessed Jun 17, 2026References to Advisories, Solutions, and Tools
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| URL | Source(s) | Tag(s) |
|---|---|---|
| https://osv.dev/vulnerability/OSEC-2026-07 | [email protected] | AdvisoryRemedy |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-295 | Improper Certificate Validation | CISA-ADP |
Affected Products
| Product | Versions |
|---|---|
| OCaml-TLS | < 2.1.0 (semver) |
CPE
Remediation
| |
Change History
5 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jun 17, 2026 | CVE Modified | CISA-ADP |
| Jun 17, 2026 | CVE Modified | [email protected] |
| Jun 17, 2026 | CVE Modified | CISA-ADP |
| Jun 16, 2026 | CVE Modified | CISA-ADP |
| Jun 15, 2026 | New CVE Received | [email protected] |