CVE-2026-40701CWE-416

NGINX ngx_http_ssl_module vulnerability

Medium · published May 13, 2026

CVSS v4.0
6.3
EPSS
1%
Percentile
52.2
In the wild
Unconfirmed
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.

The record
Technical detail
CVSS v4.0
6.3 · MEDIUM
Vector
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:L/SC:N/SI:N/SA:N
EPSS
0.00690 · 52.2th percentile
Weakness
CWE-416 · Use After Free
Published
2026-05-13T14:12Z
EPSS history
Timeline
  • 13 MAY 14:12Z
    NGINX ngx_http_ssl_module vulnerability
    cvelistv5