portable · LibreSSL ocspcheck through 4.4.0 contains a cleartext transmission vulnerability because url2host() discards the OCSP
Affects portableSource GCVE Database
Not known to be exploited · CVSS 6.3 Medium : upgrade to 4.4.1 when convenient.
Data as of 28 Oct 2026, 04:15 UTC
- Patch
- Available – fixed in 4.4.1
CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 28 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by 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
Upgrade libressl/portable to 4.4.1.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
GitHublibressl/portablepkg:github/libressl/portableOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
If you cannot patch yet, avoid using ocspcheck with OCSP responder URLs on non-standard ports or ensure network paths are trusted and protected from interception.
Description
LibreSSL's ocspcheck utility up to version 4.4.0 has a vulnerability where OCSP requests can be transmitted in cleartext when sent to HTTPS responder URLs on non-standard ports. This occurs because the function url2host() removes the OCSP URL scheme, and http_alloc() only uses TLS for port 443, leading to unencrypted transmission on other ports. As a result, on-path attackers can intercept OCSP requests and access sensitive certificate information such as serial numbers, issuer hashes, and nonces.
References
- nvd.nist.gov/vuln/detail/CVE-2026-118373 (opens in a new tab)
- github.com/openbsd/src/commit/0f7039667044d1cd252cc72134e499186da4da25 (opens in a new tab)
- ftp.openbsd.org/pub/OpenBSD/LibreSSL/libressl-4.4.0-relnotes.txt (opens in a new tab)
- github.com/libressl/portable (opens in a new tab)
- github.com/openbsd/src/blob/17a8e44328ee2505d69723a126a390a526e50370/usr.sbin/ocspcheck/http.c (opens in a new tab)
- vulncheck.com/advisories/libressl-ocspcheck-through-4.4.0-cleartext-transmission-of-ocsp-requests-via-url2host (opens in a new tab)