Protection Mechanism Vulnerabilities in Cisco Secure Firewall Software
CVE-2026-20331

9.6CRITICAL

Key Information:

Vendor

Cisco
Status
Cisco Secure Firewall Adaptive Security Appliance (asa) Software
Cisco Secure Firewall Management Center (fmc)
Cisco Secure Firewall Threat Defense (ftd) Software
Vendor
CVE Published:
16 September 2026

Badges

👾 Exploit Exists

What is CVE-2026-20331?

Cisco's Secure Adaptive Security Appliance Software and related firewall products have encountered vulnerabilities due to the failure of protective mechanisms. This situation arises as part of Cisco's dedication to enhancing security through continuous product evaluations. A recent internal review led to a robust software hardening release aimed at mitigating several identified weaknesses, classified under the Common Weakness Enumeration framework. Users are encouraged to implement the latest updates to ensure optimal security against potential threats.

Affected Version(s)

Cisco Secure Firewall Adaptive Security Appliance (ASA) Software 9.16.1

Cisco Secure Firewall Adaptive Security Appliance (ASA) Software 9.16.1.28

Cisco Secure Firewall Adaptive Security Appliance (ASA) Software 9.16.2

References

https://sec.cloudapps.cisco.com/security/center/content/C...

CVSS V3.1

Score:
9.6
Severity:
CRITICAL
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Adjacent Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
None
Scope:
Changed

Timeline

  • 👾

    Exploit known to exist

  • Vulnerability published

  • Vulnerability Reserved

.