CVE-2026-40701
Last modified
CVE-2026-40701 is a medium-severity vulnerability rated 6.3/10 on the CVSS scale. 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. EPSS estimates a 0.68% chance of exploitation in the next 30 days.
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.
Metrics
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:L
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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Weakness Enumeration
Affected Software
| Vendor | Product | Versions |
|---|---|---|
| F5 | Dos | >= 4.3.0, <= 4.7.0 |
| F5 | Dos | 4.8.0 |
| F5 | Nginx Gateway Fabric | >= 1.3.0, <= 1.6.2 |
| F5 | Nginx Gateway Fabric | >= 2.0.0, <= 2.6.0 |
| F5 | Nginx Ingress Controller | >= 3.5.0, <= 3.7.2 |
| F5 | Nginx Ingress Controller | >= 4.0.0, <= 4.0.1 |
| F5 | Nginx Ingress Controller | >= 5.0.0, <= 5.4.2 |
| 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 |
| F5 | Waf | >= 5.1.0, <= 5.8.0 |
| F5 | Waf | >= 5.9.0, <= 5.12.1 |
References
- https://my.f5.com/manage/s/article/K000161021Mitigation, Vendor Advisory
Timeline
- Published
- Last Modified
- Status
- Analyzed
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How Strix Helps
- How Strix found a critical auth bypass in etcdStrix autonomously discovered a critical authentication bypass in etcd, later designated CVE-2026-33413.
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