NGINX
CVE-2026-40701: NGINX ngx_http_ssl_module vulnerability
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.
Published
Automatic summary from the vendor's CVE record. We haven't written a full analysis of this vulnerability yet.
Affected and fixed versions
| Product / branch | Fixed in |
|---|---|
| NGINX Plus R37 | Not affected |
| NGINX Plus R36 | R36 P4 or later |
| NGINX Plus R32 | R32 P6 or later |
| NGINX Open Source 1.31 | Not affected |
| NGINX Open Source 1.19 | 1.30.1 or later |
Always confirm against the vendor advisory, which lists every fixed hotfix.
What it is
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.
Sources
KEV status, EPSS score and vendor data refreshed automatically, last on 12 Oct 2026.