CVE intelligence

CVE-2026-40701

Vulnerability intelligence

Published May 13, 2026Sources checked Nov 11, 2026

4.8MEDIUMCVSS out of 10

What this means

Review the available evidence

CVE-2026-40701 and is rated Medium severity with a CVSS score of 4.8. It is not in the current CISA KEV record we collected. That does not prove exploitation has not occurred.

What to do next

Remediation and response

Microsoft Security Response Center guidance

Vendor revision: May 17, 2026

CBL-Mariner Releases

Vendor-listed releases

1.28.3-2

CISA KEVNot listedBased on the latest collected catalog

EPSS0.7%Estimated 30-day exploitation probability

Ransomware useNot markedCISA KEV ransomware field

Threat actors0Source-linked actor relationships

Overview

What is CVE-2026-40701?

NGINX Plus and NGINX Open Source have a vulnerability in the ngx_http_ssl_module module when the ssl_verify_client directive is set to "on" or "optional," and the ssl_ocsp directive is set to "on" or the leaf parameters are configured with a resolver.

With this configuration, an unauthenticated attacker can send requests along with conditions beyond its control that may cause a heap-use-after-free error in the NGINX worker process. This vulnerability may result in limited modification of data or the NGINX worker process restarting.

Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.

Source: NVD