CVE-2026-118373

LibreSSL ocspcheck through 4.4.0 Cleartext Transmission of OCSP Requests via url2host()

6.3 Medium

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.

Attack profile

How easy it is to exploit

Attack vector: Network
Complexity: High
Privileges needed: None
User interaction: None

What an attacker can affect

Confidentiality: Low
Integrity: None
Availability: None

Exploit likelihood

0.09%Unchanged since Oct 28, 2026

What each source reports

CVE List Score used 6.3

LibreSSL ocspcheck through 4.4.0 Cleartext Transmission of OCSP Requests via url2host()

Record: CVE-2026-118373
CVSS 4.0: 6.3 MediumCVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N
CVSS 3.1: 3.7 LowCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N
Weakness: CWE-319
Updated: 2026-11-05

EUVDEUVD-2026-111549 6.3

Record: EUVD-2026-111549
CVSS 4.0: 6.3 MediumCVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N
Updated: 2026-11-05

GitHub AdvisoriesGHSA-56qc-c576-qq46 6.3

LibreSSL ocspcheck through 4.4.0 contains a cleartext transmission vulnerability because url2host...

Record: GHSA-56qc-c576-qq46
CVSS 4.0: 6.3 MediumCVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CVSS 3.1: 3.7 LowCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N
Weakness: CWE-319
Updated: 2026-11-02

NVD 6.3

Record: CVE-2026-118373
CVSS 4.0: 6.3 MediumCVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CVSS 3.1: 3.7 LowCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N
Weakness: CWE-319
Updated: 2026-11-05

OSV 6.3

LibreSSL ocspcheck through 4.4.0 Cleartext Transmission of OCSP Requests via url2host()

Record: CVE-2026-118373
CVSS 4.0: 6.3 MediumCVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N
Weakness: CWE-319
Updated: 2026-11-07

Affected products

History

History
Recorded	Changed	Sources
Nov 5, 2026	facts	CVE List
Nov 2, 2026	first indexed	CVE List, EUVD, GitHub Advisories, NVD, OSV

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2026-118373 is a medium vulnerability (CVSS 6.3) in Libressl, published October 28, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.09%, the 0th percentile. No source names a fixed version.