CVE-2026-20334: Cisco Secure Firewall Adaptive Security Appliance (ASA) Software · Improper Adherence to Coding Standards
Affects Cisco Secure Firewall Adaptive Security Appliance (ASA) SoftwareSource CVE Database V5
Not known to be exploited · CVSS 8.4 High.
Data as of 31 Oct 2026, 20:20 UTC
- EPSS
- 0.3% chance of exploitation in 30 days – higher than 33% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 16 Sep 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 31 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| CiscoCisco Secure Firewall Adaptive Security Appliance (ASA) Software | Affected
| Fixed in– |
| CiscoCisco Secure Firewall Management Center (FMC) | Affected
| Fixed in– |
| CiscoCisco Secure Firewall Threat Defense (FTD) Software | Affected
| Fixed in– |
AI-suggested
Cisco has released a software hardening update that addresses the vulnerabilities identified in this internal security review, including CVE-2026-20334. Users should apply the official Cisco updates corresponding to their affected ASA software versions to remediate this vulnerability. Since this is not a cloud service, remediation requires updating the affected software versions. No known exploits are reported in the wild at this time.
Description
CVE-2026-20334 is a high-severity vulnerability in Cisco Secure Firewall Adaptive Security Appliance (ASA) Software caused by improper adherence to coding standards related to CWE-710. Cisco conducted an internal security review that identified multiple vulnerabilities, leading to a software hardening release addressing these issues. The vulnerability affects specific versions of the ASA software and has a CVSS score of 8.4, indicating a significant risk. No known exploits are reported in the wild. The vulnerability impacts confidentiality, integrity, and availability with high privileges required and user interaction necessary.