CVE-2026-118373 Details
Description
LibreSSL ocspcheck through 4.4.0 contains a cleartext transmission vulnerability because url2host() discards the OCSP URL scheme and http_alloc() only selects TLS for port 443. On-path network attackers can read OCSP requests sent to https responder URLs on non-443 ports, exposing certificate serial numbers, issuer hashes, and nonces.
A vulnerability exists in LibreSSL's ocspcheck tool, all versions through 4.4.0, allowing for cleartext transmission of OCSP requests. The issue arises because the url2host() function ignores the OCSP URL scheme, and the http_alloc() function only enables TLS for port 443. As a result, on-path network attackers can intercept OCSP requests sent to HTTPS responder URLs on ports other than 443, exposing sensitive information such as certificate serial numbers, issuer hashes, and nonces.
Users can upgrade to LibreSSL 4.4.0 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 Oct 28, 2026CISA-ADP
Assessed Nov 5, 2026References to Advisories, Solutions, and Tools
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Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-319 | Cleartext Transmission of Sensitive Information | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| LibreSSL ocspcheck | <= 4.4.0 (semver) |
CPE
Remediation
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Change History
2 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Nov 5, 2026 | CVE Modified | CISA-ADP |
| Oct 28, 2026 | New CVE Received | [email protected] |