{"id":"CVE-2026-20349","published":"2026-08-11T17:17:48Z","modified":"2026-10-26T13:10:00Z","title":"Cisco Secure Firewall Adaptive Security Appliance (ASA) and Secure Firewall Threat Defense (FTD) Heap Inspection…","vendor":"Cisco","product":"Secure Firewall Adaptive Security Appliance (ASA) and Secure Firewall Threat Defense (FTD) ","tier":"core","eol":null,"description":{"text":"A vulnerability in the Remote Access SSL VPN service for Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Cisco Secure Firewall Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause the device to reload unexpectedly, resulting in a denial of service (DoS) condition. \r\n\r\nThis vulnerability is due to insufficient error checking when processing HTTP requests. An attacker could exploit this vulnerability by sending a crafted HTTP request to the Remote Access SSL VPN service on an affected device. A successful exploit could allow the attacker to cause the affected device to reload, resulting in a DoS condition.","provenance":"source","from":"NVD"},"summary":{"text":"The Remote Access SSL VPN service in Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Cisco Secure Firewall Threat Defense (FTD) Software contains a heap inspection flaw caused by insufficient error checking when processing HTTP requests. An unauthenticated remote attacker can exploit it by sending a crafted HTTP request to the affected Remote Access SSL VPN service, with no user interaction required, causing the device to reload unexpectedly and creating a denial-of-service condition.","provenance":"ai","model":"claude-haiku-5-5","generatedAt":"2026-10-31T04:53:59Z"},"cvss":{"score":8.6,"severity":"HIGH","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H","provenance":"source","from":"NVD"},"epss":{"score":0.0101,"percentile":0.63113,"date":"2026-10-30","provenance":"source"},"kev":{"dateAdded":"2026-08-11","dueDate":"2026-08-14","ransomware":false,"requiredAction":"Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.","notes":"https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asaftd-vpn-dos-dzv4mQFF ; BOD 26-04: https://www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk ; Forensics Triage Requirements: https://www.cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk ; https://nvd.nist.gov/vuln/detail/CVE-2026-20349","provenance":"source"},"vulncheckKev":{"dateAdded":"2026-08-11","exploitedFirstSeen":"2026-08-11","ransomware":false,"evidence":[{"url":"https://previdian.com/CVE-2026-20349","date":"2026-08-11"},{"url":"https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asaftd-vpn-dos-dzv4mQFF","date":"2026-08-11"},{"url":"https://www.cisa.gov/sites/default/files/feeds/known_exploited_vulnerabilities.json","date":"2026-08-11"},{"url":"https://www.hkcert.org/security-bulletin/cisco-products-multiple-vulnerabilities_20260812","date":"2026-08-12"},{"url":"https://eclypsium.com/blog/cve-2026-20349-someone-is-crashing-cisco-firewalls-we-need-to-talk-about-why/","date":"2026-08-19"},{"url":"https://cydome.io/maritime-cybersecurity-bulletin-august-21st-2026/","date":"2026-08-21"},{"url":"https://www.recordedfuture.com/blog/august-2026-cve-landscape","date":"2026-09-08"}],"evidenceTotal":7,"provenance":"source"},"exploited":true,"otx":{"pulseCount":31,"pulses":[{"name":"Actively_Exploited_Kev | Oct 31, 2026","url":"https://otx.alienvault.com/pulse/6ae4aefab0c2191cecd41862","created":"2026-10-30"},{"name":"Actively_Exploited_Kev | Oct 30, 2026","url":"https://otx.alienvault.com/pulse/6ae35d889ea92b4ce19c2680","created":"2026-10-29"},{"name":"Actively_Exploited_Kev | Oct 29, 2026","url":"https://otx.alienvault.com/pulse/6ae20c1db17e7057ae7d9ad1","created":"2026-10-28"},{"name":"Actively_Exploited_Kev | Oct 28, 2026","url":"https://otx.alienvault.com/pulse/6ae0ba7e0e2a97ff7b218819","created":"2026-10-27"},{"name":"Actively_Exploited_Kev | Oct 27, 2026","url":"https://otx.alienvault.com/pulse/6adf68b85c3e852f3c111d18","created":"2026-10-26"},{"name":"Actively_Exploited_Kev | Oct 24, 2026","url":"https://otx.alienvault.com/pulse/6adb740e397c3ad4799aa4cd","created":"2026-10-23"},{"name":"Actively_Exploited_Kev | Oct 23, 2026","url":"https://otx.alienvault.com/pulse/6ada236fcfba2dfa730ea482","created":"2026-10-22"},{"name":"Actively_Exploited_Kev | Oct 22, 2026","url":"https://otx.alienvault.com/pulse/6ad8d33a077cbb5cab524d80","created":"2026-10-21"},{"name":"Actively_Exploited_Kev | Oct 21, 2026","url":"https://otx.alienvault.com/pulse/6ad78130c4d1ac2be83a8b6d","created":"2026-10-20"},{"name":"Actively_Exploited_Kev | Oct 20, 2026","url":"https://otx.alienvault.com/pulse/6ad62f63c24a405a3423cc13","created":"2026-10-19"}],"provenance":"machine"},"cwes":[{"id":"CWE-244","name":"Improper Clearing of Heap Memory Before Release"}],"references":[{"url":"https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asaftd-vpn-dos-dzv4mQFF","tags":["Vendor Advisory"]},{"url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-20349","tags":["US Government Resource"]}],"techniques":[{"id":"T1190","name":"Exploit Public-Facing Application","tactics":["initial-access"],"provenance":"ai","basis":"ai-mapping","bases":["ai-mapping"],"basisDetail":"claude-haiku-5-5: Unauthenticated remote HTTP request exploits public-facing VPN service","mappingType":"exploitation_technique","evidence":[{"from":"description","quote":"could allow an unauthenticated, remote attacker to cause the device to reload","start":178,"end":255}],"model":"claude-haiku-5-5","confidence":"medium","confidenceNote":"AI-mapped from the description (quote-validated, not expert-reviewed)"},{"id":"T1499.004","name":"Application or System Exploitation","tactics":["impact"],"provenance":"ai","basis":"ai-mapping","bases":["ai-mapping"],"basisDetail":"claude-haiku-5-5: Crafted request forces device reload, causing DoS","mappingType":"primary_impact","evidence":[{"from":"description","quote":"resulting in a denial of service (DoS) condition","start":270,"end":318}],"model":"claude-haiku-5-5","confidence":"medium","confidenceNote":"AI-mapped from the description (quote-validated, not expert-reviewed)"}],"reports":[],"affected":[],"advisories":[],"euvd":{"id":"EUVD-2026-56643","url":"https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-56643","exploited":true,"exploitedSince":"2026-08-11","provenance":"source"},"exploits":[],"exploitSources":{"pocGithub":{"count":1,"skipped":0,"earliest":"2026-10-18","earliestUrl":"https://github.com/ekacs/predicted-cve-2026-20349","repos":[{"name":"ekacs/predicted-cve-2026-20349","url":"https://github.com/ekacs/predicted-cve-2026-20349","stars":1,"created":"2026-10-18"}]},"first":{"date":"2026-10-18","source":"PoC-in-GitHub","url":"https://github.com/ekacs/predicted-cve-2026-20349"},"provenance":"source"},"exploitRefs":[],"flow":[{"stage":"exploitation","techniques":["T1190"],"provenance":"ai"},{"stage":"primary","techniques":["T1499.004"],"provenance":"ai"}],"timeline":[{"date":"2026-08-11","kind":"published","label":"Published 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