CVE-2026-40701

MEDIUM 4.8

NGINX ngx_http_ssl_module vulnerability

CVSS Score

4.8

EPSS Score

0.0%

EPSS Percentile

0th

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.

CWE	CWE-416
Vendor	f5
Product	nginx plus
Published	May 13, 2026
Last Updated	May 13, 2026

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CVSS v3 Breakdown

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:L

Attack Vector

Network

Attack Complexity

High

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

Low

Integrity

None

Availability

Low

Affected Versions

F5 / NGINX Plus

R36 < R36 P4 R32 < R32 P6

F5 / NGINX Open Source

1.19.0 < 1.30.1

References

NVD ↗ CVE.org ↗ EPSS Data ↗

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

Credits

F5 acknowledges Zhenpeng (Leo) Lin of depthfirst for bringing this issue to our attention and following the highest standards of coordinated disclosure.