CVE-2026-40701
MediumCVSS 4.8Exploitation Probability (EPSS)
Low risk47th percentile - higher than 47% of all known CVEs
Summary
NGINX Plus and NGINX Open Source have a vulnerability in the ngx_http_ssl_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. In this configuration, an unauthenticated attacker can send requests that may cause a heap-use-after-free error in the NGINX worker process.
Risk Assessment
This vulnerability may result in limited modification of data or the NGINX worker process restarting, which can affect the availability of services in the organization.
Recommendation
It is recommended to disable the ssl_verify_client or ssl_ocsp directive, or apply appropriate patches to mitigate the risk associated with this vulnerability.
Original NVD description (English source)
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.