--- id: "CVE-2026-20349" kind: "vulnerability" aliases: ["CVE-2026-20349"] title: "cisco adaptive security appliance software: A vulnerability in the Remote Access SSL VPN service for Cisco Secure Firewall Adaptive Security Appliance (ASA)\u2026" severity: "high" cvss: 8.6 epss: null exploited: true status: "open" category: "infrastructure" products: [{"name": "Cisco Secure Firewall Adaptive Security Appliance (ASA) and Secure Firewall Threat Defense (FTD)", "fixed": [], "affected": "", "ecosystem": "vendor"}, {"name": "cisco adaptive security appliance software", "fixed": [], "affected": "= 9.16.1", "ecosystem": "vendor"}, {"name": "cisco adaptive security appliance software", "fixed": [], "affected": "= 9.16.1.28", "ecosystem": "vendor"}, {"name": "cisco adaptive security appliance software", "fixed": [], "affected": "= 9.16.2", "ecosystem": "vendor"}, {"name": "cisco adaptive security appliance software", "fixed": [], "affected": "= 9.16.2.3", "ecosystem": "vendor"}, {"name": "cisco adaptive security appliance software", "fixed": [], "affected": "= 9.16.2.7", "ecosystem": "vendor"}, {"name": "cisco adaptive security appliance software", "fixed": [], "affected": "= 9.16.2.11", "ecosystem": "vendor"}, {"name": "cisco adaptive security appliance software", "fixed": [], "affected": "= 9.16.2.13", "ecosystem": "vendor"}, {"name": "cisco adaptive security appliance software", "fixed": [], "affected": "= 9.16.2.14", "ecosystem": "vendor"}, {"name": "cisco adaptive security appliance software", "fixed": [], "affected": "= 9.16.3", "ecosystem": "vendor"}, {"name": "cisco adaptive security appliance software", "fixed": [], "affected": "= 9.16.3.3", "ecosystem": "vendor"}, {"name": "cisco adaptive security appliance software", "fixed": [], "affected": "= 9.16.3.14", "ecosystem": "vendor"}, {"name": "cisco adaptive security appliance software", "fixed": [], "affected": "= 9.16.3.15", "ecosystem": "vendor"}, {"name": "cisco adaptive security appliance software", "fixed": [], "affected": "= 9.16.3.19", "ecosystem": "vendor"}, {"name": "cisco adaptive security appliance software", "fixed": [], "affected": "= 9.16.3.23", "ecosystem": "vendor"}, {"name": "cisco adaptive security appliance software", "fixed": [], "affected": "= 9.16.4", "ecosystem": "vendor"}, {"name": "cisco adaptive security appliance software", "fixed": [], "affected": "= 9.16.4.9", "ecosystem": "vendor"}, {"name": "cisco adaptive security appliance software", "fixed": [], "affected": "= 9.16.4.14", "ecosystem": "vendor"}, {"name": "cisco adaptive security appliance software", "fixed": [], "affected": "= 9.16.4.19", "ecosystem": "vendor"}, {"name": "cisco adaptive security appliance software", "fixed": [], "affected": "= 9.16.4.27", "ecosystem": "vendor"}, {"name": "cisco adaptive security appliance software", "fixed": [], "affected": "= 9.16.4.38", "ecosystem": "vendor"}, {"name": "cisco adaptive security appliance software", "fixed": [], "affected": "= 9.16.4.39", "ecosystem": "vendor"}, {"name": "cisco adaptive security appliance software", "fixed": [], "affected": "= 9.16.4.42", "ecosystem": "vendor"}, {"name": "cisco adaptive security appliance software", "fixed": [], "affected": "= 9.16.4.48", "ecosystem": "vendor"}, {"name": "cisco adaptive security appliance software", "fixed": [], "affected": "= 9.16.4.55", "ecosystem": "vendor"}, {"name": "cisco adaptive security appliance software", "fixed": [], "affected": "= 9.16.4.57", "ecosystem": "vendor"}, {"name": "cisco adaptive security appliance software", "fixed": [], "affected": "= 9.16.4.61", "ecosystem": "vendor"}, {"name": "cisco adaptive security appliance software", "fixed": [], "affected": "= 9.16.4.62", "ecosystem": "vendor"}, {"name": "cisco adaptive security appliance software", "fixed": [], "affected": "= 9.16.4.67", "ecosystem": "vendor"}, {"name": "cisco adaptive security appliance software", "fixed": [], "affected": "= 9.16.4.70", "ecosystem": "vendor"}, {"name": "cisco adaptive security appliance software", "fixed": [], "affected": "= 9.16.4.71", "ecosystem": "vendor"}, {"name": "cisco adaptive security appliance software", "fixed": [], "affected": "= 9.16.4.76", "ecosystem": "vendor"}, {"name": "cisco adaptive security appliance software", "fixed": [], "affected": "= 9.16.4.82", "ecosystem": "vendor"}, {"name": "cisco adaptive security appliance software", "fixed": [], "affected": "= 9.16.4.84", "ecosystem": "vendor"}, {"name": "cisco adaptive security appliance software", "fixed": [], "affected": "= 9.16.4.85", "ecosystem": "vendor"}, {"name": "cisco adaptive security appliance software", "fixed": [], "affected": "= 9.16.4.89", "ecosystem": "vendor"}, {"name": "cisco adaptive security appliance software", "fixed": [], "affected": "= 9.16.4.92", "ecosystem": "vendor"}, {"name": "cisco adaptive security appliance software", "fixed": [], "affected": "= 9.18.1", "ecosystem": "vendor"}, {"name": "cisco adaptive security appliance software", "fixed": [], "affected": "= 9.18.1.3", "ecosystem": "vendor"}, {"name": "cisco adaptive security appliance software", "fixed": [], "affected": "= 9.18.2", "ecosystem": "vendor"}, {"name": "cisco adaptive security appliance software", "fixed": [], "affected": "= 9.18.2.5", "ecosystem": "vendor"}] ecosystems: ["vendor"] tags: ["asa", "cisco", "exploited", "firewall", "ftd", "infrastructure", "self-hosted"] not_affected_if: ["no-asa-or-ftd-deployed"] published_at: "2026-08-11T00:00:00+00:00" first_seen_at: "2026-10-23T19:11:51+00:00" updated_at: "2026-10-23T23:44:51+00:00" sources: [{"source": "kev", "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2026-20349", "first_seen_at": "2026-10-23T19:11:51+00:00"}, {"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-20349", "first_seen_at": "2026-10-23T23:44:51+00:00"}] --- # cisco adaptive security appliance software: A vulnerability in the Remote Access SSL VPN service for Cisco Secure Firewall Adaptive Security Appliance (ASA)… A heap inspection flaw in Cisco ASA and Secure Firewall Threat Defense lets an unauthenticated remote attacker force the device to reload unexpectedly. The result is a denial of service on the firewall, and CISA lists it as known exploited. _Summary, check and fix written by a model from the sources; labelled as such._ ## Affected - vendor:Cisco Secure Firewall Adaptive Security Appliance (ASA) and Secure Firewall Threat Defense (FTD) affected ? fixed ? - vendor:cisco adaptive security appliance software affected = 9.16.1 fixed ? - vendor:cisco adaptive security appliance software affected = 9.16.1.28 fixed ? - vendor:cisco adaptive security appliance software affected = 9.16.2 fixed ? - vendor:cisco adaptive security appliance software affected = 9.16.2.3 fixed ? - vendor:cisco adaptive security appliance software affected = 9.16.2.7 fixed ? - vendor:cisco adaptive security appliance software affected = 9.16.2.11 fixed ? - vendor:cisco adaptive security appliance software affected = 9.16.2.13 fixed ? - vendor:cisco adaptive security appliance software affected = 9.16.2.14 fixed ? - vendor:cisco adaptive security appliance software affected = 9.16.3 fixed ? - vendor:cisco adaptive security appliance software affected = 9.16.3.3 fixed ? - vendor:cisco adaptive security appliance software affected = 9.16.3.14 fixed ? - vendor:cisco adaptive security appliance software affected = 9.16.3.15 fixed ? - vendor:cisco adaptive security appliance software affected = 9.16.3.19 fixed ? - vendor:cisco adaptive security appliance software affected = 9.16.3.23 fixed ? - vendor:cisco adaptive security appliance software affected = 9.16.4 fixed ? - vendor:cisco adaptive security appliance software affected = 9.16.4.9 fixed ? - vendor:cisco adaptive security appliance software affected = 9.16.4.14 fixed ? - vendor:cisco adaptive security appliance software affected = 9.16.4.19 fixed ? - vendor:cisco adaptive security appliance software affected = 9.16.4.27 fixed ? - vendor:cisco adaptive security appliance software affected = 9.16.4.38 fixed ? - vendor:cisco adaptive security appliance software affected = 9.16.4.39 fixed ? - vendor:cisco adaptive security appliance software affected = 9.16.4.42 fixed ? - vendor:cisco adaptive security appliance software affected = 9.16.4.48 fixed ? - vendor:cisco adaptive security appliance software affected = 9.16.4.55 fixed ? - vendor:cisco adaptive security appliance software affected = 9.16.4.57 fixed ? - vendor:cisco adaptive security appliance software affected = 9.16.4.61 fixed ? - vendor:cisco adaptive security appliance software affected = 9.16.4.62 fixed ? - vendor:cisco adaptive security appliance software affected = 9.16.4.67 fixed ? - vendor:cisco adaptive security appliance software affected = 9.16.4.70 fixed ? - vendor:cisco adaptive security appliance software affected = 9.16.4.71 fixed ? - vendor:cisco adaptive security appliance software affected = 9.16.4.76 fixed ? - vendor:cisco adaptive security appliance software affected = 9.16.4.82 fixed ? - vendor:cisco adaptive security appliance software affected = 9.16.4.84 fixed ? - vendor:cisco adaptive security appliance software affected = 9.16.4.85 fixed ? - vendor:cisco adaptive security appliance software affected = 9.16.4.89 fixed ? - vendor:cisco adaptive security appliance software affected = 9.16.4.92 fixed ? - vendor:cisco adaptive security appliance software affected = 9.18.1 fixed ? - vendor:cisco adaptive security appliance software affected = 9.18.1.3 fixed ? - vendor:cisco adaptive security appliance software affected = 9.18.2 fixed ? - vendor:cisco adaptive security appliance software affected = 9.18.2.5 fixed ? ## How to check Check the ASA or FTD software version against the Cisco advisory for CVE-2026-20349 (affected and fixed versions not given in the sources). Review device logs for unexpected reloads. ## Fix Apply the Cisco fixed software release for CVE-2026-20349 and follow the mitigations in the Cisco advisory (version not given in the sources). If no mitigation exists, follow CISA BOD 26-04 guidance or discontinue use of the product. ## Timeline - 2026-10-23T19:11:51+00:00 kev https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2026-20349 - 2026-10-23T23:44:51+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-20349 ## From the sources Cisco Secure Firewall Adaptive Security Appliance (ASA) and Secure Firewall Threat Defense (FTD) contain a heap inspection vulnerability that could allow an unauthenticated, remote attacker to cause the device to reload unexpectedly, resulting in a denial of service (DoS) condition. CISA required action: 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. --- _Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_