{"schemaVersion":3,"id":"CVE-2026-20135","aliases":[],"status":"published","duplicateOf":null,"title":null,"description":"A vulnerability in the TLS 1.3 implementation in Cisco Secure Firewall Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause an affected device to reload unexpectedly, resulting in a denial of service (DoS) condition.\n\nThis vulnerability is due to improper buffer management during the TLS 1.3 connection. An attacker could exploit this vulnerability by sending a crafted TLS 1.3 packet to an affected system through a TLS 1.3-enabled listening socket. A successful exploit could allow the attacker to cause the LINA process to crash, which would cause the device to reload. The reload can happen before or after authentication of the connection.Note: TLS 1.3 connections include both data traffic and user-management traffic.","dates":{"published":"2026-09-16T20:12:09.389Z","modified":"2026-09-17T13:40:57.832Z","reserved":null,"kevAdded":[],"kevDue":[]},"cvss":{"headline":{"score":8.6,"severity":"high","version":"3.1","versionLabel":"v3.1","source":"CVE.org","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H","computed":false,"selection":"backend-summary"},"metrics":[{"version":"3.1","versionLabel":"v3.1","source":"CVE.org","score":8.6,"severity":"high","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H","exploitability":null,"impact":null,"computed":false},{"version":"3.1","versionLabel":"v3.1","source":"NVD","score":8.6,"severity":"high","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H","exploitability":null,"impact":null,"computed":false}]},"epss":{"probability":0.00457,"percentile":0.38292,"severity":"low","asOf":"2026-10-19T00:00:00.000Z","change":{"pp":0,"baselineDate":"2026-09-19T00:00:00.000Z","baselineScore":0.00457},"history":[{"date":"2026-09-17T00:00:00.000Z","score":0.00457,"percentile":null},{"date":"2026-09-18T00:00:00.000Z","score":0.00457,"percentile":null},{"date":"2026-09-19T00:00:00.000Z","score":0.00457,"percentile":null},{"date":"2026-09-20T00:00:00.000Z","score":0.00457,"percentile":null},{"date":"2026-09-21T00:00:00.000Z","score":0.00457,"percentile":null},{"date":"2026-09-22T00:00:00.000Z","score":0.00457,"percentile":null},{"date":"2026-09-23T00:00:00.000Z","score":0.00457,"percentile":null},{"date":"2026-09-24T00:00:00.000Z","score":0.00457,"percentile":null},{"date":"2026-09-25T00:00:00.000Z","score":0.00457,"percentile":null},{"date":"2026-09-26T00:00:00.000Z","score":0.00457,"percentile":null},{"date":"2026-09-27T00:00:00.000Z","score":0.00457,"percentile":null},{"date":"2026-09-28T00:00:00.000Z","score":0.00457,"percentile":null},{"date":"2026-09-29T00:00:00.000Z","score":0.00457,"percentile":null},{"date":"2026-09-30T00:00:00.000Z","score":0.00457,"percentile":null},{"date":"2026-10-01T00:00:00.000Z","score":0.00457,"percentile":null},{"date":"2026-10-02T00:00:00.000Z","score":0.00457,"percentile":null},{"date":"2026-10-03T00:00:00.000Z","score":0.00457,"percentile":null},{"date":"2026-10-04T00:00:00.000Z","score":0.00457,"percentile":null},{"date":"2026-10-05T00:00:00.000Z","score":0.00457,"percentile":null},{"date":"2026-10-06T00:00:00.000Z","score":0.00457,"percentile":null},{"date":"2026-10-07T00:00:00.000Z","score":0.00457,"percentile":null},{"date":"2026-10-08T00:00:00.000Z","score":0.00457,"percentile":null},{"date":"2026-10-09T00:00:00.000Z","score":0.00457,"percentile":null},{"date":"2026-10-10T00:00:00.000Z","score":0.00457,"percentile":null},{"date":"2026-10-11T00:00:00.000Z","score":0.00457,"percentile":null},{"date":"2026-10-12T00:00:00.000Z","score":0.00457,"percentile":null},{"date":"2026-10-13T00:00:00.000Z","score":0.00457,"percentile":null},{"date":"2026-10-14T00:00:00.000Z","score":0.00457,"percentile":null},{"date":"2026-10-15T00:00:00.000Z","score":0.00457,"percentile":null},{"date":"2026-10-16T00:00:00.000Z","score":0.00457,"percentile":null},{"date":"2026-10-17T00:00:00.000Z","score":0.00457,"percentile":null},{"date":"2026-10-18T00:00:00.000Z","score":0.00457,"percentile":null},{"date":"2026-10-19T00:00:00.000Z","score":0.00457,"percentile":0.38292}],"last30":[{"date":"2026-09-19T00:00:00.000Z","score":0.00457,"percentile":null},{"date":"2026-09-20T00:00:00.000Z","score":0.00457,"percentile":null},{"date":"2026-09-21T00:00:00.000Z","score":0.00457,"percentile":null},{"date":"2026-09-22T00:00:00.000Z","score":0.00457,"percentile":null},{"date":"2026-09-23T00:00:00.000Z","score":0.00457,"percentile":null},{"date":"2026-09-24T00:00:00.000Z","score":0.00457,"percentile":null},{"date":"2026-09-25T00:00:00.000Z","score":0.00457,"percentile":null},{"date":"2026-09-26T00:00:00.000Z","score":0.00457,"percentile":null},{"date":"2026-09-27T00:00:00.000Z","score":0.00457,"percentile":null},{"date":"2026-09-28T00:00:00.000Z","score":0.00457,"percentile":null},{"date":"2026-09-29T00:00:00.000Z","score":0.00457,"percentile":null},{"date":"2026-09-30T00:00:00.000Z","score":0.00457,"percentile":null},{"date":"2026-10-01T00:00:00.000Z","score":0.00457,"percentile":null},{"date":"2026-10-02T00:00:00.000Z","score":0.00457,"percentile":null},{"date":"2026-10-03T00:00:00.000Z","score":0.00457,"percentile":null},{"date":"2026-10-04T00:00:00.000Z","score":0.00457,"percentile":null},{"date":"2026-10-05T00:00:00.000Z","score":0.00457,"percentile":null},{"date":"2026-10-06T00:00:00.000Z","score":0.00457,"percentile":null},{"date":"2026-10-07T00:00:00.000Z","score":0.00457,"percentile":null},{"date":"2026-10-08T00:00:00.000Z","score":0.00457,"percentile":null},{"date":"2026-10-09T00:00:00.000Z","score":0.00457,"percentile":null},{"date":"2026-10-10T00:00:00.000Z","score":0.00457,"percentile":null},{"date":"2026-10-11T00:00:00.000Z","score":0.00457,"percentile":null},{"date":"2026-10-12T00:00:00.000Z","score":0.00457,"percentile":null},{"date":"2026-10-13T00:00:00.000Z","score":0.00457,"percentile":null},{"date":"2026-10-14T00:00:00.000Z","score":0.00457,"percentile":null},{"date":"2026-10-15T00:00:00.000Z","score":0.00457,"percentile":null},{"date":"2026-10-16T00:00:00.000Z","score":0.00457,"percentile":null},{"date":"2026-10-17T00:00:00.000Z","score":0.00457,"percentile":null},{"date":"2026-10-18T00:00:00.000Z","score":0.00457,"percentile":null},{"date":"2026-10-19T00:00:00.000Z","score":0.00457,"percentile":0.38292}]},"kev":{"state":"not-listed","entries":[],"listedCount":0,"totalCatalogs":3,"catalogs":[{"source":"cisa","label":"CISA","listed":false,"entry":null},{"source":"enisa","label":"ENISA","listed":false,"entry":null},{"source":"circl","label":"CIRCL","listed":false,"entry":null}]},"ransomware":{"state":"none-recorded","sources":[]},"exploits":[],"exploitCount":0,"weaknesses":[{"id":"CWE-415","name":"Double Free","description":"The product calls free() twice on the same memory address.","type":"weakness","status":"Draft","abstraction":"Variant","likelihoodOfExploit":"High","url":"https://cwe.mitre.org/data/definitions/415.html"}],"affected":[{"vendor":"cisco","product":"cisco secure firewall threat defense (ftd) software","name":"Cisco Secure Firewall Threat Defense (FTD) Software","label":"cisco secure firewall threat defense (ftd) software","ecosystem":null,"cpePart":"a","purl":null,"purlType":null,"versions":[{"text":"7.0.0","noFixRecorded":false,"fixedIn":null},{"text":"7.0.0.1","noFixRecorded":false,"fixedIn":null},{"text":"7.0.1","noFixRecorded":false,"fixedIn":null},{"text":"7.0.1.1","noFixRecorded":false,"fixedIn":null},{"text":"7.0.2","noFixRecorded":false,"fixedIn":null},{"text":"7.2.0","noFixRecorded":false,"fixedIn":null},{"text":"7.0.2.1","noFixRecorded":false,"fixedIn":null},{"text":"7.0.3","noFixRecorded":false,"fixedIn":null},{"text":"7.2.0.1","noFixRecorded":false,"fixedIn":null},{"text":"7.0.4","noFixRecorded":false,"fixedIn":null},{"text":"7.2.1","noFixRecorded":false,"fixedIn":null},{"text":"7.0.5","noFixRecorded":false,"fixedIn":null},{"text":"7.3.0","noFixRecorded":false,"fixedIn":null},{"text":"7.2.2","noFixRecorded":false,"fixedIn":null},{"text":"7.2.3","noFixRecorded":false,"fixedIn":null},{"text":"7.3.1","noFixRecorded":false,"fixedIn":null},{"text":"7.2.4","noFixRecorded":false,"fixedIn":null},{"text":"7.0.6","noFixRecorded":false,"fixedIn":null},{"text":"7.2.5","noFixRecorded":false,"fixedIn":null},{"text":"7.2.4.1","noFixRecorded":false,"fixedIn":null},{"text":"7.3.1.1","noFixRecorded":false,"fixedIn":null},{"text":"7.4.0","noFixRecorded":false,"fixedIn":null},{"text":"7.0.6.1","noFixRecorded":false,"fixedIn":null},{"text":"7.2.5.1","noFixRecorded":false,"fixedIn":null},{"text":"7.4.1","noFixRecorded":false,"fixedIn":null},{"text":"7.2.6","noFixRecorded":false,"fixedIn":null},{"text":"7.0.6.2","noFixRecorded":false,"fixedIn":null},{"text":"7.4.1.1","noFixRecorded":false,"fixedIn":null},{"text":"7.2.7","noFixRecorded":false,"fixedIn":null},{"text":"7.2.5.2","noFixRecorded":false,"fixedIn":null},{"text":"7.3.1.2","noFixRecorded":false,"fixedIn":null},{"text":"7.2.8","noFixRecorded":false,"fixedIn":null},{"text":"7.6.0","noFixRecorded":false,"fixedIn":null},{"text":"7.4.2","noFixRecorded":false,"fixedIn":null},{"text":"7.2.8.1","noFixRecorded":false,"fixedIn":null},{"text":"7.0.6.3","noFixRecorded":false,"fixedIn":null},{"text":"7.4.2.1","noFixRecorded":false,"fixedIn":null},{"text":"7.2.9","noFixRecorded":false,"fixedIn":null},{"text":"7.0.7","noFixRecorded":false,"fixedIn":null},{"text":"7.7.0","noFixRecorded":false,"fixedIn":null},{"text":"7.4.2.2","noFixRecorded":false,"fixedIn":null},{"text":"7.2.10","noFixRecorded":false,"fixedIn":null},{"text":"7.6.1","noFixRecorded":false,"fixedIn":null},{"text":"7.4.2.3","noFixRecorded":false,"fixedIn":null},{"text":"7.0.8","noFixRecorded":false,"fixedIn":null},{"text":"7.6.2","noFixRecorded":false,"fixedIn":null},{"text":"7.7.10","noFixRecorded":false,"fixedIn":null},{"text":"7.7.11","noFixRecorded":false,"fixedIn":null},{"text":"7.0.8.1","noFixRecorded":false,"fixedIn":null},{"text":"7.6.2.1","noFixRecorded":false,"fixedIn":null},{"text":"7.7.10.1","noFixRecorded":false,"fixedIn":null},{"text":"7.4.2.4","noFixRecorded":false,"fixedIn":null},{"text":"7.2.10.2","noFixRecorded":false,"fixedIn":null},{"text":"7.4.3","noFixRecorded":false,"fixedIn":null},{"text":"7.6.4","noFixRecorded":false,"fixedIn":null},{"text":"7.4.4","noFixRecorded":false,"fixedIn":null},{"text":"7.0.9","noFixRecorded":false,"fixedIn":null},{"text":"7.2.11","noFixRecorded":false,"fixedIn":null}],"versionsText":"7.0.0 | 7.0.0.1 | 7.0.1 | 7.0.1.1 | 7.0.2 | 7.2.0 | 7.0.2.1 | 7.0.3 | 7.2.0.1 | 7.0.4 | 7.2.1 | 7.0.5 | 7.3.0 | 7.2.2 | 7.2.3 | 7.3.1 | 7.2.4 | 7.0.6 | 7.2.5 | 7.2.4.1 | 7.3.1.1 | 7.4.0 | 7.0.6.1 | 7.2.5.1 | 7.4.1 | 7.2.6 | 7.0.6.2 | 7.4.1.1 | 7.2.7 | 7.2.5.2 | 7.3.1.2 | 7.2.8 | 7.6.0 | 7.4.2 | 7.2.8.1 | 7.0.6.3 | 7.4.2.1 | 7.2.9 | 7.0.7 | 7.7.0 | 7.4.2.2 | 7.2.10 | 7.6.1 | 7.4.2.3 | 7.0.8 | 7.6.2 | 7.7.10 | 7.7.11 | 7.0.8.1 | 7.6.2.1 | 7.7.10.1 | 7.4.2.4 | 7.2.10.2 | 7.4.3 | 7.6.4 | 7.4.4 | 7.0.9 | 7.2.11","eol":null,"hubHref":"/vendor/cisco/cisco_secure_firewall_threat_defense_ftd_software"}],"affectedCount":1,"eol":{"hasEol":false,"count":0},"references":[{"url":"https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ftd-tls1.3-dos-dLxwFWgF","label":"sec.cloudapps.cisco.com/security/…","hostname":"sec.cloudapps.cisco.com","tags":[]}],"lineage":{"upstream":[],"downstream":[],"duplicates":[],"related":[]},"timeline":[{"kind":"published","date":"2026-09-16T20:12:09.389Z","label":"Published","detail":"Vulnerability first disclosed.","source":null},{"kind":"modified","date":"2026-09-17T13:40:57.832Z","label":"Last modified","detail":"Vulnerability information updated.","source":null}],"risk":{"score":34,"level":"medium","profile":"Default","thresholds":{"critical":75,"high":50,"medium":25,"low":10}},"meta":{"dataAsOf":"2026-10-20T03:58:12.255Z","stale":false,"partial":false}}