CVE-2026-40701

MEDIUM EPSS 47.7%
Published May 13, 20261mo ago · Modified Jun 23, 20261w ago
6.3 CVSS 4.0
Medium
Find Similar
Published May 13, 2026 1mo ago
Last Modified Jun 23, 2026 1w ago

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 Details

Base Score
6.3
Exploitability
Impact
Vector string
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
Attack Vector Network
Attack Complexity Low
Privileges Required None
User Interaction None
Scope X

Threat Intelligence

EPSS Exploit Probability
47.7% percentile
Exploit & Patch Status
No Known Exploit
No Patch Available

Weaknesses 1

CWE-416 Use After Free Memory Safety

Affected Products 13

VendorProductVersionRange
f5dos*≥4.3.0  –  ≤4.7.0
f5dos4.8.0any
f5nginx_gateway_fabric*≥1.3.0  –  ≤1.6.2
f5nginx_gateway_fabric*≥2.0.0  –  ≤2.6.0
f5nginx_ingress_controller*≥3.5.0  –  ≤3.7.2
f5nginx_ingress_controller*≥4.0.0  –  ≤4.0.1
f5nginx_ingress_controller*≥5.0.0  –  ≤5.4.2
f5nginx_instance_manager*≥2.16.0  –  ≤2.22.0
f5nginx_open_source*≥1.19.0  –  ≤1.30.0
f5nginx_plus*≥r32  –  ≤r36
f5waf*≥4.9.0  –  ≤4.16.0
f5waf*≥5.1.0  –  ≤5.8.0
f5waf*≥5.9.0  –  ≤5.12.1

References 1

  • my.f5.com https://my.f5.com/manage/s/article/K000161021
    MitigationVendor Advisory

Remediation

No remediation data recorded yet

Check vendor advisories and the NVD entry for patch availability.