Vulnerability · Published Oct 28, 2026 · Assigned by VulnCheck

CVE-2026-118372LibreSSL ocspcheck through 4.4.0 CRLF Injection via AIA OCSP URL Path

Low 3.7

In plain English

A low-severity security flaw in LibreSSL from OpenBSD. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.1% (higher than 4% of all known vulnerabilities).

Severity (CVSS 3.1)3.7Low

Exploit odds (30 days)0.1%top 96.2% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

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.

Affected products (as reported)

Vendor	Product	Versions
OpenBSD	LibreSSL	0 – through 4.4.0

Weakness: CWE-93 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N

References

https://github.com/openbsd/src/commit/6efdc4cce3fac9fa7208a9452f84de34c5a68e9f patch
https://github.com/openbsd/src/commit/3adb7688a5bcfb675fa6d8b10e242022d620a23d patch
https://github.com/openbsd/src/blob/17a8e44328ee2505d69723a126a390a526e50370/usr.sbin/ocspcheck/http.c#L344 technical-description
https://github.com/openbsd/src/blob/17a8e44328ee2505d69723a126a390a526e50370/usr.sbin/ocspcheck/ocspcheck.c#L154 technical-description
LibreSSL 4.4.0 Release Notes release-notes
https://github.com/libressl/portable product
VulnCheck Advisory: LibreSSL ocspcheck through 4.4.0 CRLF Injection via AIA OCSP URL Path third-party-advisory