{"id":"CVE-2026-97629","state":"PUBLISHED","title":"NGINX ngx_http_ssl_module vulnerability","description":"Description\nWhen NGINX Plus or NGINX Open Source is configured with ssl_session_cache \n\nshared:name:size\n\nwithout an explicit ssl_session_ticket_key file directives to automatically rotate SSL session ticket keys, a remote unauthenticated attacker is able to forge client SSL sessions \n\nin a non-deterministic manner that is beyond the attacker's control. An attacker could leverage this vulnerability to bypass verification of client certificates.\n\nImpact\n\n\nThis vulnerability can lead to the exposure of resources or functionality to unintended actors, possibly providing attackers with access to sensitive information. There is no control plane exposure; this is a data plane issue only.\n\n\n\n\n\n\nNote: Software versions which have reached End of Technical Support (EoTS) are not evaluated.","publishedAt":"2026-10-14T14:40:26.740Z","updatedAt":"2026-10-29T16:59:42.330Z","severity":{"score":8.3,"label":"High","version":"4.0","vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:L/VA:N/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":"37.1.0","status":"affected","lessThan":"37.1.0.1","versionType":"custom"},{"version":"37.0.0","status":"affected","lessThan":"37.0.5.1","versionType":"custom"},{"version":"R36","status":"affected","lessThan":"*","versionType":"custom"},{"version":"R35","status":"affected","lessThan":"*","versionType":"custom"},{"version":"R34","status":"affected","lessThan":"*","versionType":"custom"},{"version":"R33","status":"affected","lessThan":"*","versionType":"custom"}],"modules":["ngx_http_ssl_module"]},{"vendor":"F5","product":"NGINX Open Source","defaultStatus":"unknown","versions":[{"version":"1.31.0","status":"affected","lessThan":"1.31.7","versionType":"custom"},{"version":"1.30.0","status":"affected","lessThan":"1.30.6","versionType":"custom"},{"version":"1.23.3","status":"affected","lessThan":"*","versionType":"custom"}],"modules":["ngx_http_ssl_module"]}],"references":["https://my.f5.com/manage/s/article/K000162606"],"weaknesses":["CWE-908"],"ingestedAt":"2026-10-29T20:13:43.249Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/97xxx/CVE-2026-97629.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-97629","state":"PUBLISHED","datePublished":"2026-10-14T14:40:26.740Z","dateUpdated":"2026-10-29T16:59:42.330Z","assignerShortName":"f5","assignerOrgId":"9dacffd4-cb11-413f-8451-fbbfd4ddc0ab","dateReserved":"2026-09-30T17:31:09.133Z"},"containers":{"cna":{"title":"NGINX ngx_http_ssl_module vulnerability","descriptions":[{"lang":"en","value":"Description\nWhen NGINX Plus or NGINX Open Source is configured with ssl_session_cache \n\nshared:name:size\n\nwithout an explicit ssl_session_ticket_key file directives to automatically rotate SSL session ticket keys, a remote unauthenticated attacker is able to forge client SSL sessions \n\nin a non-deterministic manner that is beyond the attacker's control. An attacker could leverage this vulnerability to bypass verification of client certificates.\n\nImpact\n\n\nThis vulnerability can lead to the exposure of resources or functionality to unintended actors, possibly providing attackers with access to sensitive information. There is no control plane exposure; this is a data plane issue only.\n\n\n\n\n\n\nNote: Software versions which have reached End of Technical Support (EoTS) are not evaluated."}],"affected":[{"vendor":"F5","product":"NGINX Plus","defaultStatus":"unknown","versions":[{"version":"37.1.0","status":"affected","lessThan":"37.1.0.1","versionType":"custom"},{"version":"37.0.0","status":"affected","lessThan":"37.0.5.1","versionType":"custom"},{"version":"R36","status":"affected","lessThan":"*","versionType":"custom"},{"version":"R35","status":"affected","lessThan":"*","versionType":"custom"},{"version":"R34","status":"affected","lessThan":"*","versionType":"custom"},{"version":"R33","status":"affected","lessThan":"*","versionType":"custom"}],"modules":["ngx_http_ssl_module"]},{"vendor":"F5","product":"NGINX Open Source","defaultStatus":"unknown","versions":[{"version":"1.31.0","status":"affected","lessThan":"1.31.7","versionType":"custom"},{"version":"1.30.0","status":"affected","lessThan":"1.30.6","versionType":"custom"},{"version":"1.23.3","status":"affected","lessThan":"*","versionType":"custom"}],"modules":["ngx_http_ssl_module"]}],"references":[{"url":"https://my.f5.com/manage/s/article/K000162606","tags":["vendor-advisory"]}],"metrics":[{"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}],"cvssV3_1":{"version":"3.1","attackVector":"NETWORK","attackComplexity":"HIGH","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"LOW","availabilityImpact":"NONE","baseSeverity":"MEDIUM","baseScore":6.5,"vectorString":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:N"}},{"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}],"cvssV4_0":{"version":"4.0","attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"PRESENT","privilegesRequired":"NONE","userInteraction":"NONE","vulnConfidentialityImpact":"HIGH","subConfidentialityImpact":"NONE","vulnIntegrityImpact":"LOW","subIntegrityImpact":"NONE","vulnAvailabilityImpact":"NONE","subAvailabilityImpact":"NONE","Safety":"NOT_DEFINED","Automatable":"NOT_DEFINED","Recovery":"NOT_DEFINED","valueDensity":"NOT_DEFINED","vulnerabilityResponseEffort":"NOT_DEFINED","providerUrgency":"NOT_DEFINED","baseSeverity":"HIGH","baseScore":8.3,"vectorString":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-908","lang":"en","description":"CWE-908 Use of Uninitialized Resource","type":"CWE"}]}],"providerMetadata":{"shortName":"f5","orgId":"9dacffd4-cb11-413f-8451-fbbfd4ddc0ab","dateUpdated":"2026-10-29T16:59:42.330Z"},"datePublic":"2026-10-14T14:00:00.000Z","impacts":[{"capecId":"CAPEC-59","descriptions":[{"lang":"en","value":"CAPEC-59 Session Credential Falsification through Prediction"}]}],"workarounds":[{"lang":"en","value":"Do not enable automatic rotation of SSL session ticket keys: \n\noption a) remove the \"ssl_session_cache shared:name:size\" directive;\n https://nginx.org/en/docs/http/ngx_http_ssl_module.html#ssl_session_cache  \n\noption b) switch to loading static ticket keys from a file using the \"ssl_session_ticket_key\" directive.\n https://nginx.org/en/docs/http/ngx_http_ssl_module.html#ssl_session_ticket_key  \n\nSystems that disable session tickets (\"ssl_session_tickets off;\") are not affected.\n https://nginx.org/en/docs/http/ngx_http_ssl_module.html#ssl_session_tickets","supportingMedia":[{"type":"text/html","base64":false,"value":"<span style=\"background-color: rgb(255, 255, 255);\">Do not enable automatic rotation of SSL session ticket keys: <br><br>option a) remove the \"ssl_session_cache </span><b>shared</b><span style=\"background-color: rgb(255, 255, 255);\">:name:size\" directive;<br><a target=\"_blank\" rel=\"nofollow\" href=\"https://nginx.org/en/docs/http/ngx_http_ssl_module.html#ssl_session_cache\">https://nginx.org/en/docs/http/ngx_http_ssl_module.html#ssl_session_cache</a> <br><br>option b) switch to loading static ticket keys from a file using the \"ssl_session_ticket_key\" directive.<br><a target=\"_blank\" rel=\"nofollow\" href=\"https://nginx.org/en/docs/http/ngx_http_ssl_module.html#ssl_session_ticket_key\">https://nginx.org/en/docs/http/ngx_http_ssl_module.html#ssl_session_ticket_key</a> <br><br>Systems that disable session tickets (\"ssl_session_tickets off;\") are not affected.<br><a target=\"_blank\" rel=\"nofollow\" href=\"https://nginx.org/en/docs/http/ngx_http_ssl_module.html#ssl_session_tickets\">https://nginx.org/en/docs/http/ngx_http_ssl_module.html#ssl_session_tickets</a></span>"}]}],"credits":[{"lang":"en","value":"F5 acknowledges PhiNode Labs, Gyejin Lee (QED Audit), Liviu-Alexandru Bud & Marc Luchian, Anthropic & Ada Logics, and Vivek Parikh of Zero-Day Research Labs for bringing this issue to our attention and following the highest standards of coordinated disclosure.","type":"finder"}],"source":{"discovery":"EXTERNAL"},"x_generator":{"engine":"F5 SIRTBot v1.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2026-97629","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"version":"2.0.3","timestamp":"2026-10-15T15:52:47.244695Z"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-15T16:43:47.036Z"}}]}}}