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CVE-2026-20331: Protection Mechanism Failure in Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software

0
Critical
VulnerabilityCVE-2026-20331cvecve-2026-20331
Published: 09/16/2026 (09/16/2026, 16:56:18 UTC)
Source: CVE Database V5
Vendor/Project: Cisco
Product: Cisco Secure Firewall Adaptive Security Appliance (ASA) Software

Description

As part of Cisco's ongoing commitment to proactive security and product quality, the Cisco Secure Adaptive Security Appliance Software, Cisco Secure Firewall Threat Defense Software and Cisco Secure Firewall Management Center Software engineering team has conducted a comprehensive internal security review. This review resulted in a software hardening release that addresses multiple internally discovered vulnerabilities.   The vulnerabilities tracked by CVE-2026-20331 are related to the failure of protection mechanisms issues that are grouped under the Common Weakness Enumeration (CWE) Pillar CWE-693.

CVSS v3.1

Score 9.6critical

Attack Vector
Adjacent Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Changed
Confidentiality
High
Integrity
High
Availability
Low
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:L

Affected software

Cisco

Cisco Secure Firewall Adaptive Security Appliance (ASA) Software

Affected versions
=9.16.1=9.16.1.28=9.16.2=9.16.2.3=9.16.2.7=9.16.2.11=9.16.2.13=9.16.2.14=9.16.3.3=9.16.3=9.16.3.14=9.16.3.15=9.18.1.3=9.18.2=9.16.3.19=9.16.3.23=9.18.2.5=9.16.4=9.18.2.7=9.16.4.9=9.18.2.8=9.16.4.14=9.18.3=9.16.4.18=9.18.3.39=9.16.4.19=9.18.3.46=9.16.4.27=9.18.3.53=9.18.3.55=9.16.4.38=9.16.4.39=9.18.3.56=9.20.1=9.16.4.42=9.18.4=9.20.1.5=9.18.4.5=9.16.4.48=9.18.4.8=9.20.2=9.16.4.55=9.18.4.22=9.20.2.10=9.16.4.57=9.18.4.24=9.20.2.21=9.16.4.61=9.18.4.29=9.20.2.22=9.16.4.62=9.18.4.34=9.20.3=9.16.4.67=9.16.4.70=9.18.4.40=9.23.1=9.22.1.1=9.16.4.71=9.20.3.4=9.18.4.47=9.20.3.7=9.16.4.76=9.20.3.9=9.18.4.50=9.22.1.3=9.20.3.10=9.22.1.2=9.18.4.52=9.20.3.13=9.22.1.6=9.18.4.53=9.16.4.82=9.22.2=9.20.3.16=9.19.1.42=9.18.4.57=9.16.4.84=9.23.1.3=9.20.3.20=9.22.2.4=9.23.1.7=9.20.4=9.22.2.9=9.23.1.13=9.20.4.7=9.22.2.13=9.18.4.66=9.20.4.10=9.23.1.19=9.16.4.85=9.22.2.14=9.18.4.67=9.24.1=9.18.4.68=9.23.1.22=9.20.4.14=9.22.2.20=9.18.4.71=9.20.4.19=9.23.1.26=9.16.4.89=9.22.2.32=9.18.4.76=9.22.3=9.24.1.5=9.20.4.22=9.24.1.9=9.20.4.28=9.22.3.5=9.16.4.92=9.18.4.135=9.23.1.195=9.20.4.30=9.24.1.155=9.23.1.32=9.24.1.11=9.20.4.34=9.18.4.82=9.24.10=9.23.1.211=9.20.4.235=9.24.1.221=9.22.3.191

Cisco

Cisco Secure Firewall Management Center (FMC)

Affected versions
=7.0.0=7.0.0.1=7.0.1=7.0.1.1=7.0.2=7.2.0=7.0.2.1=7.0.3=7.2.0.1=7.0.4=7.2.1=7.0.5=7.3.0=7.2.2=7.3.1=7.2.3=7.2.3.1=7.2.4=7.0.6=7.2.4.1=7.2.5=7.3.1.1=7.4.0=7.0.6.1=7.2.5.1=7.4.1=7.2.6=7.4.1.1=7.0.6.2=7.2.7=7.2.5.2=7.3.1.2=7.2.8=7.6.0=7.4.2=7.2.8.1=7.0.6.3=7.4.2.1=7.2.9=7.0.7=7.7.0=7.4.2.2=7.2.10=7.6.1=7.4.2.3=7.0.8=7.6.2=7.7.10=7.2.10.1=7.0.8.1=7.6.2.1=7.2.10.2=7.7.10.1=7.4.2.4=7.4.3=7.6.3=7.7.11=7.6.4=10.0.0=7.4.4=7.4.5=7.0.9=7.2.11=7.7.12=7.6.5=7.4.6=10.0.1=7.4.7

Cisco

Cisco Secure Firewall Threat Defense (FTD) Software

Affected versions
=7.0.0.1=7.0.1=7.0.1.1=7.0.2=7.0.2.1=7.0.3=7.0.4=7.0.5=7.3.0=7.3.1=7.0.6=7.3.1.1=7.4.0=7.0.6.1=7.4.1=7.0.6.2=7.4.1.1=7.3.1.2=7.6.0=7.4.2=7.0.6.3=7.4.2.1=7.0.7=7.7.0=7.4.2.2=7.6.1=7.4.2.3=7.0.8=7.6.2=7.7.10=7.7.11=7.0.8.1=7.6.2.1=7.7.10.1=7.4.2.4=7.4.3=7.6.4=10.0.0=7.4.4=7.0.9=7.4.7

Technical Details

Data Version
5.2
Assigner Short Name
cisco
Date Reserved
2025-10-08T11:59:15.412Z
Cvss Version
3.1
State
PUBLISHED

Threat ID: 6aaacb9c55bf5e2cf5e5c27e

Added to database: 09/16/2026, 17:02:20 UTC

Last updated: 09/16/2026, 17:02:20 UTC

Views: 1

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