{"id":"CVE-2026-40701","state":"PUBLISHED","title":"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.\n\n\n\n Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.","publishedAt":"2026-05-13T14:12:43.588Z","updatedAt":"2026-05-13T16:07:37.463Z","severity":{"score":6.3,"label":"Medium","version":"4.0","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","source":"f5"},"assigner":"f5","products":["F5 NGINX Plus","F5 NGINX Open Source"],"affected":[{"vendor":"F5","product":"NGINX Plus","defaultStatus":"unknown","versions":[{"version":"R37","status":"unaffected","lessThan":"*","versionType":"custom"},{"version":"R36","status":"affected","lessThan":"R36 P4","versionType":"custom"},{"version":"R32","status":"affected","lessThan":"R32 P6","versionType":"custom"}],"modules":["ngx_http_ssl_module"]},{"vendor":"F5","product":"NGINX Open Source","defaultStatus":"unaffected","versions":[{"version":"1.31.0","status":"unaffected","lessThan":"*","versionType":"semver"},{"version":"1.19.0","status":"affected","lessThan":"1.30.1","versionType":"semver"}],"modules":["ngx_http_ssl_module"]}],"references":["https://my.f5.com/manage/s/article/K000161021"],"weaknesses":["CWE-416"],"ingestedAt":"2026-10-29T20:11:57.932Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/40xxx/CVE-2026-40701.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-40701","state":"PUBLISHED","datePublished":"2026-05-13T14:12:43.588Z","dateUpdated":"2026-05-13T16:07:37.463Z","assignerShortName":"f5","assignerOrgId":"9dacffd4-cb11-413f-8451-fbbfd4ddc0ab","dateReserved":"2026-04-30T23:04:27.950Z"},"containers":{"cna":{"title":"NGINX ngx_http_ssl_module vulnerability","descriptions":[{"lang":"en","value":"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.\n\n\n\n Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated."}],"affected":[{"vendor":"F5","product":"NGINX Plus","defaultStatus":"unknown","versions":[{"version":"R37","status":"unaffected","lessThan":"*","versionType":"custom"},{"version":"R36","status":"affected","lessThan":"R36 P4","versionType":"custom"},{"version":"R32","status":"affected","lessThan":"R32 P6","versionType":"custom"}],"modules":["ngx_http_ssl_module"]},{"vendor":"F5","product":"NGINX Open Source","defaultStatus":"unaffected","versions":[{"version":"1.31.0","status":"unaffected","lessThan":"*","versionType":"semver"},{"version":"1.19.0","status":"affected","lessThan":"1.30.1","versionType":"semver"}],"modules":["ngx_http_ssl_module"]}],"references":[{"url":"https://my.f5.com/manage/s/article/K000161021","tags":["vendor-advisory","patch"]}],"metrics":[{"cvssV3_1":{"attackComplexity":"HIGH","attackVector":"NETWORK","availabilityImpact":"LOW","baseScore":4.8,"baseSeverity":"MEDIUM","confidentialityImpact":"LOW","integrityImpact":"NONE","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:L","version":"3.1"},"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}]},{"cvssV4_0":{"Automatable":"NOT_DEFINED","Recovery":"NOT_DEFINED","Safety":"NOT_DEFINED","attackComplexity":"LOW","attackRequirements":"PRESENT","attackVector":"NETWORK","baseScore":6.3,"baseSeverity":"MEDIUM","privilegesRequired":"NONE","providerUrgency":"NOT_DEFINED","subAvailabilityImpact":"NONE","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","userInteraction":"NONE","valueDensity":"NOT_DEFINED","vectorString":"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","version":"4.0","vulnAvailabilityImpact":"LOW","vulnConfidentialityImpact":"LOW","vulnIntegrityImpact":"NONE","vulnerabilityResponseEffort":"NOT_DEFINED"},"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}]}],"problemTypes":[{"descriptions":[{"cweId":"CWE-416","description":"CWE-416 Use After Free","lang":"en","type":"CWE"}]}],"providerMetadata":{"shortName":"f5","orgId":"9dacffd4-cb11-413f-8451-fbbfd4ddc0ab","dateUpdated":"2026-05-13T14:12:43.588Z"},"credits":[{"lang":"en","type":"finder","value":"F5 acknowledges Zhenpeng (Leo) Lin of depthfirst for bringing this issue to our attention and following the highest standards of coordinated disclosure."}],"datePublic":"2026-05-13T14:00:00.000Z","source":{"discovery":"EXTERNAL"},"x_generator":{"engine":"F5 SIRTBot v1.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-05-13T15:55:34.604451Z","id":"CVE-2026-40701","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-05-13T16:07:37.463Z"}}]}}}