Vulnerability · Published Oct 28, 2026 · Assigned by VulnCheck

CVE-2026-118371LibreSSL through 4.4.0 CRLF Injection via OCSP_sendreq_new() Request Line

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 3% of all known vulnerabilities).

Severity (CVSS 3.1)3.7Low

Exploit odds (30 days)0.1%top 97.0% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

LibreSSL through 4.4.0 contains a CRLF injection vulnerability in the libcrypto OCSP_sendreq_new() and OCSP_parse_url() functions, which write unvalidated request paths into the OCSP POST request line. Attackers can embed carriage return and line feed characters in a certificate's Authority Information Access OCSP URI to inject HTTP headers or split requests sent to responders and proxies.

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/d3f7195f4849d8a699cea4a3a67677f4b3dc1591 patch
https://github.com/openbsd/src/blob/3903c41d301d66facec69f7bf776b182cbc5ed62/lib/libcrypto/ocsp/ocsp_ht.c#L184 technical-description
LibreSSL 4.4.0 Release Notes release-notes
https://github.com/libressl/portable product
VulnCheck Advisory: LibreSSL through 4.4.0 CRLF Injection via OCSP_sendreq_new() Request Line third-party-advisory