CyberSecBulletin
CVE-2026-20334NVD status: Awaiting Analysis

Cisco Secure Firewall Adaptive Security…: Improper Adherence to Coding Standards

Published Updated By the CyberSecBulletin desk

CVE-2026-20334 is a high-severity improper adherence to coding standards vulnerability in Cisco Secure Firewall Adaptive Security Appliance (ASA) Software from Cisco, with a CVSS 3.1 base score of 8.4 out of 10. It can be exploited remotely over the network by an attacker with administrator privileges, but only if a user takes part, for example by opening a link or file. Affected Cisco Secure Firewall Adaptive Security Appliance (ASA) Software versions: 9.16.1; 9.16.1.28; 9.16.2, and others listed below. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.39% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Check which version of Cisco Secure Firewall Adaptive Security Appliance (ASA) Software you run against the affected versions below, and install the vendor's latest release.
  2. Because the attack needs a user to take part, warn users about unexpected links and files related to this product until it is patched.

Affected products and versions

VendorProductAffected versionsFixed in
CiscoCisco Secure Firewall Adaptive Security Appliance (ASA) Software9.16.1; 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; and 32 more rangesNot stated
CiscoCisco Secure Firewall Management Center (FMC)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; and 32 more rangesNot stated
CiscoCisco Secure Firewall Threat Defense (FTD) Software7.0.0.1; 7.0.1; 7.0.1.1; 7.0.2; 7.0.2.1; 7.0.3; 7.0.4; 7.0.5; and 32 more rangesNot stated

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
HighAdministrator-level access is required first.
User interaction
RequiredA user must take an action such as opening a file or link.
Scope
ChangedThe attack can reach beyond the vulnerable component into other systems.
Confidentiality
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:H/I:H/A:H. Scored by CNA (cisco.com).

Official 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-2026-20334 are related to issues concerning improper adherence to coding standards that are grouped under the Common Weakness Enumeration (CWE) Pillar CWE-710.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Improper Adherence to Coding Standards

The product does not follow certain coding rules for development.

How developers prevent this class of flaw

  • Select and require coding standards. Ensure that they include security concerns.
  • Closely follow coding standards, possibly enforcing them upon checkin of the code into a source control system or with periodic analyses.

More Improper Adherence to Coding Standards vulnerabilities (CWE-710)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in Cisco Secure Firewall Adaptive Security Appliance (ASA) Software

All Cisco Secure Firewall Adaptive Security Appliance (ASA) Software vulnerabilities

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