Skip to main content
VulnerabilityPublished Updated

CVE-2026-45389: OCaml-TLS · Improper Certificate Validation

Source CVE Database V5

0

Not known to be exploited · CVSS 7.4 High · fixed in 2.1.0 : patch OCaml-TLS soon.

Data as of 26 Oct 2026, 14:05 UTC

CVSS 3.1 base score
7.4High
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.1% chance of exploitation in 30 days – higher than 8% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Affects
OCaml-TLS before 2.1.0
Patch
Available – fixed in 2.1.0
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 15 Jun 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

What to do

AI-suggested

If you cannot patch yet, avoid relying on OCaml-TLS versions prior to 2.1.0 for client certificate authentication or implement additional certificate validation checks externally to ensure proper KeyUsage and ExtendedKeyUsage enforcement.

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

Community reviews

Loading reviews…