Exploited vulnerability CISA KEV
CVE-2026-20349: Cisco Secure Firewall Adaptive Security Appliance (ASA) and Secure Firewall Threat Defense (FTD) Heap Inspection Vulnerability
CVE-2026-20349 is a vulnerability in Cisco Secure Firewall Adaptive Security Appliance (ASA) and Secure Firewall Threat Defense (FTD) that CISA added to its Known Exploited Vulnerabilities catalog on August 11, 2026, meaning there is evidence it is being exploited. US federal civilian agencies must complete the required action by August 14, 2026.
CVE-2026-20349 is a vulnerability in Cisco Secure Firewall Adaptive Security Appliance (ASA) and Secure Firewall Threat Defense (FTD) that CISA added to its Known Exploited Vulnerabilities catalog on August 11, 2026, meaning there is evidence it is being exploited. US federal civilian agencies must complete the required action by August 14, 2026.
- CVE ID
- CVE-2026-20349
- Vendor / project
- Cisco
- Product
- Secure Firewall Adaptive Security Appliance (ASA) and Secure Firewall Threat Defense (FTD)
- Added to KEV
- Due date
- Days to remediate
- 3
- Known ransomware use
- Unknown
- Weakness
- CWE-244
CISA 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.
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.
Notes and references #
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
This page reproduces CISA’s catalog entry and is not indexed by search engines until an editor adds analysis. [Editorial analysis pending]