CVE-2026-20331CWE-693

CVE-2026-20331

Critical · published September 16, 2026

CVSS v3.1
9.6
EPSS
0%
Percentile
13.0
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
9.6 · CRITICAL
Vector
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:L
CVSS v4.0
Not supplied
EPSS
0.00229 · 13.0th percentile
Weakness
CWE-693 · Protection Mechanism Failure
Published
2026-09-16T21:17Z
References (1)
https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-hardening-asaftdfmc-uvpPROhN · [email protected]
EPSS history
Timeline
  • 18 SEP 03:58Z
    EPSS moved — → 0%
    epss
  • 16 SEP 16:56Z
    Cisco Secure Adaptive Security Appliance Software, Secure Firewall Threat Defense Software and Secure Firewall Management Center Software Hardening Release - Protection Mechanism Failure Vulnerabilities
    cvelistv5