6.3
MEDIUM CVSS 4.0
CVE-2026-118372
LibreSSL ocspcheck through 4.4.0 CRLF Injection via AIA OCSP URL Path
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.

INFO

Published Date :

Oct. 28, 2026, 3:17 a.m.

Last Modified :

Oct. 28, 2026, 3:17 a.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2026-118372 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Openbsd libressl
CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 3.1 LOW 83251b91-4cc7-4094-a5c7-464a1b83ea10
CVSS 3.1 LOW MITRE-CVE
CVSS 3.1 LOW [email protected]
CVSS 4.0 MEDIUM 83251b91-4cc7-4094-a5c7-464a1b83ea10
CVSS 4.0 MEDIUM [email protected]
Solution
Update LibreSSL to patch CRLF injection affecting OCSP URI paths.
  • Update LibreSSL to a version later than 4.4.0.
  • Verify OCSP URI path handling for control characters.
  • Ensure HTTP POST requests sanitize input paths.
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-118372 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-118372 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-118372 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-118372 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • New CVE Received by [email protected]

    Oct. 28, 2026

    Action Type Old Value New Value
    Added 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.
    Added CVSS V4.0 AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
    Added CVSS V3.1 AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N
    Added CWE CWE-93
    Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/118xxx/CVE-2026-118372.json">CVE-2026-118372</a>
    Added Reference https://ftp.openbsd.org/pub/OpenBSD/LibreSSL/libressl-4.4.0-relnotes.txt
    Added Reference https://github.com/libressl/portable
    Added Reference https://github.com/openbsd/src/blob/17a8e44328ee2505d69723a126a390a526e50370/usr.sbin/ocspcheck/http.c#L344
    Added Reference https://github.com/openbsd/src/blob/17a8e44328ee2505d69723a126a390a526e50370/usr.sbin/ocspcheck/ocspcheck.c#L154
    Added Reference https://github.com/openbsd/src/commit/3adb7688a5bcfb675fa6d8b10e242022d620a23d
    Added Reference https://github.com/openbsd/src/commit/6efdc4cce3fac9fa7208a9452f84de34c5a68e9f
    Added Reference https://www.vulncheck.com/advisories/libressl-ocspcheck-through-4.4.0-crlf-injection-via-aia-ocsp-url-path
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.