🔥 This vulnerability is being actively exploited in the wild (CISA Known Exploited Vulnerabilities catalog)
CVE-2026-20349: Cisco Secure Firewall Adaptive Security Appliance (ASA) and Secure Firewall Threat Defense (FTD) Heap Inspection Vulnerability
Summary
Cisco Secure Firewall ASA and FTD devices have a heap inspection vulnerability (a flaw in how the device manages memory) that allows remote attackers to crash the device without needing to log in, causing a denial of service (DoS, where the system becomes unavailable). This vulnerability is currently being exploited by attackers in real-world attacks.
Solution / Mitigation
Apply mitigations in accordance with vendor instructions from Cisco's security advisory at https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asaftd-vpn-dos-dzv4mQFF, following CISA's BOD 26-04 guidance for prioritizing security updates. If mitigations are unavailable, discontinue use of the product. The due date for patching is 2026-08-14.
Vulnerability Details
EPSS: 0.0%
Yes
🔥 Actively Exploited
August 10, 2026
Classification
Taxonomy References
Original source: https://nvd.nist.gov/vuln/detail/CVE-2026-20349
First tracked: August 11, 2026 at 08:01 PM
Classified by LLM (prompt v3) · confidence: 95%