CVE Vulnerabilities

CVE-2026-40701

Use After Free

Published: May 13, 2026 | Modified: Jun 23, 2026
CVSS 3.x
N/A
Source:
NVD
CVSS 2.x
RedHat/V2
RedHat/V3
4.8 MODERATE
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:L
Ubuntu
MEDIUM
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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.

Weakness

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 Any operations using the original pointer are no longer valid because the memory “belongs” to the code that operates on the new pointer.

Affected Software

NameVendorStart VersionEnd Version
DosF54.3.0 (including)4.7.0 (including)
DosF54.8.0 (including)4.8.0 (including)
Nginx_gateway_fabricF51.3.0 (including)1.6.2 (including)
Nginx_gateway_fabricF52.0.0 (including)2.6.0 (including)
Nginx_ingress_controllerF53.5.0 (including)3.7.2 (including)
Nginx_ingress_controllerF54.0.0 (including)4.0.1 (including)
Nginx_ingress_controllerF55.0.0 (including)5.4.2 (including)
Nginx_instance_managerF52.16.0 (including)2.22.0 (including)
Nginx_open_sourceF51.19.0 (including)1.30.0 (including)
Nginx_plusF5r32 (including)r36 (including)
WafF54.9.0 (including)4.16.0 (including)
WafF55.1.0 (including)5.8.0 (including)
WafF55.9.0 (including)5.12.1 (including)
NginxUbuntuesm-infra-legacy/trusty*
NginxUbuntuesm-infra-legacy/xenial*
NginxUbuntuesm-infra/bionic*
NginxUbuntuesm-infra/focal*
NginxUbuntuesm-infra/xenial*
NginxUbuntujammy*
NginxUbuntunoble*
NginxUbuntuquesting*
NginxUbunturesolute*

Potential Mitigations

References