CVE-2026-40701

Published: May 13, 2026Modified: Jun 23, 2026

6.3

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/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

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:XShow less

Source: f5sirt@f5.com (Secondary)

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.

Affected (13)

Products: F5: Dos, Nginx Gateway Fabric, Nginx Ingress Controller, Nginx Instance Manager, Nginx Open Source, Nginx Plus, Waf

7 products

Dos

Nginx Gateway Fabric

Nginx Ingress Controller

Nginx Instance Manager

Nginx Open Source

Nginx Plus

Waf

Configuration A

13 vulnerable

Vulnerable Software	Affected Versions
F5 Dos	From 4.3.0 to 4.7.0
F5 Dos	Version 4.8.0
F5 Nginx Gateway Fabric	From 1.3.0 to 1.6.2
F5 Nginx Gateway Fabric	From 2.0.0 to 2.6.0
F5 Nginx Ingress Controller	From 3.5.0 to 3.7.2
F5 Nginx Ingress Controller	From 4.0.0 to 4.0.1
F5 Nginx Ingress Controller	From 5.0.0 to 5.4.2
F5 Nginx Instance Manager	From 2.16.0 to 2.22.0
F5 Nginx Open Source	From 1.19.0 to 1.30.0
F5 Nginx Plus	From r32 to r36
F5 Waf	From 4.9.0 to 4.16.0
F5 Waf	From 5.1.0 to 5.8.0
F5 Waf	From 5.9.0 to 5.12.1

Related CWEs

CWE-416

Use After Free

The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.

References (1)

https://my.f5.com/manage/s/article/K000161021

Source: f5sirt@f5.com

MitigationVendor Advisory

Timeline

No history available yet.