Low severity · published Oct 28, 2026
CVE-2026-118373
LibreSSL ocspcheck through 4.4.0 Cleartext Transmission of OCSP Requests via url2host()
New
3.7
CVSS
0.1%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N
Attack vector
Network
Complexity
High
Privileges
None
User interaction
None
Confidentiality
Low
Integrity
None
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.1% · higher than 0% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
LI
LibreSSL · OpenBSD
through 4.4.0 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-118373
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-118373
patch
https://github.com/openbsd/src/commit/0f7039667044d1cd252cc72134e499186da4da25
technical-description
https://github.com/openbsd/src/blob/17a8e44328ee2505d69723a126a390a526e50370/usr.sbin/ocspcheck/http.c#L299
release-notes
https://ftp.openbsd.org/pub/OpenBSD/LibreSSL/libressl-4.4.0-relnotes.txt
product
https://github.com/libressl/portable
third-party-advisory
https://www.vulncheck.com/advisories/libressl-ocspcheck-through-4.4.0-cleartext-transmission-of-ocsp-requests-via-url2host
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