CVE-2026-20349
Heap Inspection in Cisco Secure Firewall Adaptive Security Appliance (ASA) and Secure Firewall Threat Defense (FTD). CISA confirmed attackers exploit it and added it to its Known Exploited Vulnerabilities catalog on 11 August 2026.
- Product
- Cisco Secure Firewall Adaptive Security Appliance (ASA) and Secure Firewall Threat Defense (FTD)
- Added to CISA's catalog
- Federal fix-by date
- Ransomware
- No known use in ransomware campaigns
- Vendor advisories
- Sources
- CISA’s catalog, NVD entry
CISA’s description.
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.
More from Cisco this year.
- CVE-2026-76418 Unchecked Return Value to NULL Pointer Dereference, added
- CVE-2026-76519 Relative Path Traversal, added
- CVE-2026-76504 Hex Encoding, added
- CVE-2026-76460 Incorrect Use of Privileged APIs, added
- CVE-2026-76461 SQL Injection, added
- CVE-2026-20079 Firewall Management Center Authentication Bypass Using an Alternate Path or Channel, added
- CVE-2026-20316 Secure Firewall Management Center Use of Hard-coded Password, added
- CVE-2008-4128 Cross-Site Request Forgery, added
Every flaw CISA confirmed exploited in the last 30 days is on the exploit watch. This is not security advice. Check the vendor’s advisory before acting. From CISA’s catalog of 4 November 2026.