Vulnerability Description
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.
CVSS Score
MEDIUM
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| F5 | Dos | >= 4.3.0, <= 4.7.0 |
| F5 | Nginx Gateway Fabric | >= 1.3.0, <= 1.6.2 |
| F5 | Nginx Ingress Controller | >= 3.5.0, <= 3.7.2 |
| F5 | Nginx Instance Manager | >= 2.16.0, <= 2.22.0 |
| F5 | Nginx Open Source | >= 1.19.0, <= 1.30.0 |
| F5 | Nginx Plus | >= r32, <= r36 |
| F5 | Waf | >= 4.9.0, <= 4.16.0 |
Related Weaknesses (CWE)
References
- https://my.f5.com/manage/s/article/K000161021MitigationVendor Advisory
FAQ
What is CVE-2026-40701?
CVE-2026-40701 is a vulnerability with a CVSS score of 4.8 (MEDIUM). 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 ...
How severe is CVE-2026-40701?
CVE-2026-40701 has been rated MEDIUM with a CVSS base score of 4.8/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-40701?
Check the references section above for vendor advisories and patch information. Affected products include: F5 Dos, F5 Nginx Gateway Fabric, F5 Nginx Ingress Controller, F5 Nginx Instance Manager, F5 Nginx Open Source.