CVE-2026-118372: medium-severity vulnerability in OpenBSD LibreSSL
LibreSSL ocspcheck through 4.4.0 CRLF Injection via AIA OCSP URL Path
Published
E-mail alert when it lands in KEV, gets a public PoC or its score goes up.
13Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 6.3epss 0.1%
LibreSSL ocspcheck through 4.4.0 contains a CRLF injection vulnerability that allows attackers to inject HTTP headers by embedding CR/LF sequences in a certificate's AIA OCSP URI path. Because url2host() copies the path without rejecting control characters and http_open() places it in the POST request line, attackers can inject headers or split OCSP requests sent to the responder host.
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N
Affected products
OpenBSD · LibreSSLRelated CVEs — OpenBSD LibreSSL
In the same product, most dangerous first.
CVE-2026-118374HIGHLibreSSL ocspcheck through 4.4.0 Memory Exhaustion via Unbounded OCSP HTTP ResponseEPSS 0.2%CVE-2026-118371MEDIUMLibreSSL through 4.4.0 CRLF Injection via OCSP_sendreq_new() Request LineEPSS 0.1%CVE-2026-118373MEDIUMLibreSSL ocspcheck through 4.4.0 Cleartext Transmission of OCSP Requests via url2host()EPSS 0.1%
References
https://ftp.openbsd.org/pub/OpenBSD/LibreSSL/libressl-4.4.0-relnotes.txthttps://github.com/libressl/portablehttps://github.com/openbsd/src/blob/17a8e44328ee2505d69723a126a390a526e50370/usr.sbin/ocspcheck/http.c#L344https://github.com/openbsd/src/blob/17a8e44328ee2505d69723a126a390a526e50370/usr.sbin/ocspcheck/ocspcheck.c#L154https://github.com/openbsd/src/commit/3adb7688a5bcfb675fa6d8b10e242022d620a23dhttps://github.com/openbsd/src/commit/6efdc4cce3fac9fa7208a9452f84de34c5a68e9fhttps://www.vulncheck.com/advisories/libressl-ocspcheck-through-4.4.0-crlf-injection-via-aia-ocsp-url-path