CVE-2026-40701
NGINX ngx_http_ssl_module vulnerability
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.
How to fix CVE-2026-40701
To remediate CVE-2026-40701, upgrade the affected package to a fixed version below.
- —upgrade to 1.28.3-r1 or later
- —upgrade to 1.30.1 or later
- —upgrade to 1.30.1 or later
- —upgrade to 1.18.0-6.1+deb11u6 or later
Is CVE-2026-40701 being exploited?
Low — EPSS is 0.0%, meaning exploitation activity has not been observed at scale.
Affected packages (4)
- from 0, < 1.28.3-r1
- >= 1.19.0, < 1.30.1
- >= 1.19.0, < 1.30.1
- from 0, < 1.18.0-6.1+deb11u6
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 4.0 | — | 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 |
| osv | CVSS 3.1 | MEDIUM4.8 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:L |