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VulnerabilityPublished

CVE-2026-118373: OpenBSD LibreSSL · Cleartext Transmission

Affects OpenBSD LibreSSLSource CVE Database V5

0

Not known to be exploited · CVSS 6.3 Medium.

Data as of 28 Oct 2026, 02:42 UTC

CVSS 4.0 base score
6.3Medium
How severe the flaw is on the 0–10 CVSS scale.
CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 28 Oct 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

Affected software

ProductAffectedFixed in
OpenBSDLibreSSLAffected
  • <=4.4.0
Fixed in–
GitHubLibreSSLpkg:github/LibreSSLOther threatsAffected
  • <=4.4.0
Fixed in–

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

Until a fix is available, avoid configuring OCSP responders on non-443 ports or use network-level encryption to protect OCSP traffic. Monitor vendor communications for updates.

Description

CVE-2026-118373 is a vulnerability in LibreSSL's ocspcheck component up to version 4.4.0 that causes cleartext transmission of sensitive OCSP request data. The issue arises because the function url2host() removes the OCSP URL scheme, and http_alloc() only uses TLS for port 443. As a result, OCSP requests sent to HTTPS responder URLs on non-443 ports are transmitted without encryption, exposing certificate serial numbers, issuer hashes, and nonces to on-path attackers.

References

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