Vulnerability intelligence
CVE-2026-20329 and is rated Critical severity with a CVSS score of 9.9. It is not in the current CISA KEV record we collected. That does not prove exploitation has not occurred.
To assist customers in patching and to streamline the disclosure process, Cisco has grouped these issues by their underlying vulnerability class - Common Weakness Enumeration (CWE) - and assigned a single Common Vulnerabilities and Exposures Identifier (CVE ID) to each CWE grouping.
To remediate these vulnerabilities, Cisco strongly recommends that customers upgrade to the fixed software that is indicated in the advisories.
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-2026-20329 are related to issues concerning improper handling of exceptional conditions that are grouped under the Common Weakness Enumeration (CWE) Pillar CWE-703.
Source: NVD
Cisco Security Advisories · Updated Sep 18, 2026
These vulnerabilities affect the following Cisco products, regardless of device configuration:
Secure Firewall ASA Software
Secure FTD Software
Secure FMC Software
For information about which Cisco software releases are vulnerable, see the Fixed Software section of this advisory.
There are no workarounds that address these vulnerabilities.
To remediate these vulnerabilities and avoid future exposure as described in this advisory, Cisco strongly recommends that customers upgrade to the fixed software indicated in this advisory.
In the following table, the left column lists Cisco software releases. The center column lists hot fixes that are affected by the vulnerabilities that are described in this advisory, and the right column indicates the first software release that includes the fix for these vulnerabilities. Customers who installed one of the listed hot fix releases must install the listed first fixed release.
Cisco Secure Firewall ASA Software Release | Affected Hot Fix Release | First Fixed Release |
|---|---|---|
9.16 and earlier | N/A | 9.16.4.103 |
9.18 | 9.18.4.135 | 9.18.4.94 |
9.20 | 9.20.4.235 | 9.20.4.49 |
9.22 | 9.22.3.191 | 9.22.3.26 |
9.23 | 9.23.1.195 9.23.1.211 | 9.23.1.47 |
9.24 | 9.24.1.155 9.24.1.221 | 9.24.1.26 |
In the following table, the left column lists Cisco software releases. The right column indicates whether a release is affected by the vulnerabilities that are described in this advisory and the first release that includes the fix for these vulnerabilities.
Cisco Secure FTD Software Release and Secure FMC Software Release | First Fixed Release |
|---|---|
7.0 and earlier | 7.0.10 |
7.2 | 7.2.12 |
7.4 | 7.4.8 |
7.6 | 7.6.6 |
7.7 | 7.7.13 |
10.0 | 10.0.2 |
10.1 | 10.1.0 |
Cisco strongly recommends that customers upgrade to the first fixed releases in the preceding tables because they include fixes for multiple vulnerabilities. For more information, see Cisco Secure Firewall Adaptive Security Appliance, Secure Firewall Threat Defense, and Secure Firewall Management Center Software Hardening Release: September 2026.
The Cisco Product Security Incident Response Team (PSIRT) validates only the affected and fixed release information that is documented in this advisory.
Except as otherwise noted previously, the Cisco PSIRT is not aware of any public announcements or malicious use of the vulnerabilities that are described in this advisory.