CVE-2026-20349

HIGHCVSS 8.6Known Exploited

CISA Known Exploited Vulnerability

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

Remediation deadline: August 14, 2026

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.

Timeline

Published:August 11th, 2026 5:17 PM

Last modified:August 12th, 2026 3:02 PM

Added to KEV:August 11th, 2026

CVSS Scoring

CVSS v3: 8.6 (HIGH)

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H

Affected Software

From NVD CPE configuration data

Vendors

cisco

Products

adaptive_security_appliance_softwaresecure_firewall_threat_defense

Weaknesses (CWE)

CWE-244

References & Reports

Advisories, patches, and third-party reports

Source: NIST NVD · Data may lag official sources by up to one minute