CVE-2026-20154

Cisco Secure Firewall Adaptive Security Appliance Software and Secure Firewall Threat Defense Software Logging Denial of Service

View on CVE.org

Published Sep 16, 2026 CVSS 3.1 · 8.6 High EPSS < 1% KEV · Not listed

Description

A vulnerability in the system rate-limiting process for syslog message 419002 of Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Cisco Secure Firewall Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause high CPU utilization on an affected device, resulting in a denial of service (DoS) condition.

This vulnerability is due to improper rate limiting for syslog message 419002. An attacker could exploit this vulnerability by sending a flood of TCP synchronization (SYN) packets to an affected device. A successful exploit could allow the attacker to cause high CPU utilization, resulting in performance degradation. 

Affected Products

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions

Cisco

Cisco Secure Firewall Adaptive Security Appliance (ASA) Software

unknown

Version	Status	Constraints
`9.16.1`	affected	—
`9.16.1.28`	affected	—
`9.16.2`	affected	—
`9.16.2.3`	affected	—
`9.16.2.7`	affected	—
`9.16.2.11`	affected	—
`9.16.2.13`	affected	—
`9.16.2.14`	affected	—
`9.16.3.3`	affected	—
`9.16.3`	affected	—
`9.16.3.14`	affected	—
`9.18.1`	affected	—
`9.16.3.15`	affected	—
`9.18.1.3`	affected	—
`9.18.2`	affected	—
`9.16.3.19`	affected	—
`9.16.3.23`	affected	—
`9.18.2.5`	affected	—
`9.16.4`	affected	—
`9.18.2.7`	affected	—
`9.19.1`	affected	—
`9.16.4.9`	affected	—
`9.18.2.8`	affected	—
`9.16.4.14`	affected	—
`9.18.3`	affected	—
`9.19.1.5`	affected	—
`9.16.4.18`	affected	—
`9.19.1.9`	affected	—
`9.18.3.39`	affected	—
`9.16.4.19`	affected	—
`9.19.1.12`	affected	—
`9.18.3.46`	affected	—
`9.16.4.27`	affected	—
`9.19.1.18`	affected	—
`9.18.3.53`	affected	—
`9.18.3.55`	affected	—
`9.16.4.38`	affected	—
`9.16.4.39`	affected	—
`9.18.3.56`	affected	—
`9.20.1`	affected	—
`9.16.4.42`	affected	—
`9.19.1.22`	affected	—
`9.18.4`	affected	—
`9.20.1.5`	affected	—
`9.18.4.5`	affected	—
`9.19.1.24`	affected	—
`9.16.4.48`	affected	—
`9.18.4.8`	affected	—
`9.20.2`	affected	—
`9.19.1.27`	affected	—
`9.16.4.55`	affected	—
`9.18.4.22`	affected	—
`9.20.2.10`	affected	—
`9.16.4.57`	affected	—
`9.19.1.28`	affected	—
`9.18.4.24`	affected	—
`9.20.2.21`	affected	—
`9.16.4.61`	affected	—
`9.19.1.31`	affected	—
`9.18.4.29`	affected	—
`9.20.2.22`	affected	—
`9.16.4.62`	affected	—
`9.18.4.34`	affected	—
`9.20.3`	affected	—
`9.16.4.67`	affected	—
`9.16.4.70`	affected	—
`9.18.4.40`	affected	—
`9.23.1`	affected	—
`9.22.1.1`	affected	—
`9.16.4.71`	affected	—
`9.20.3.4`	affected	—
`9.18.4.47`	affected	—
`9.20.3.7`	affected	—
`9.19.1.37`	affected	—
`9.16.4.76`	affected	—
`9.20.3.9`	affected	—
`9.19.1.38`	affected	—
`9.18.4.50`	affected	—
`9.22.1.3`	affected	—
`9.20.3.10`	affected	—
`9.22.1.2`	affected	—
`9.18.4.52`	affected	—
`9.20.3.13`	affected	—
`9.22.1.6`	affected	—
`9.18.4.53`	affected	—
`9.16.4.82`	affected	—
`9.22.2`	affected	—
`9.20.3.16`	affected	—
`9.19.1.42`	affected	—
`9.18.4.57`	affected	—
`9.16.4.84`	affected	—
`9.23.1.3`	affected	—
`9.20.3.20`	affected	—
`9.22.2.4`	affected	—
`9.23.1.7`	affected	—
`9.20.4`	affected	—
`9.22.2.9`	affected	—
`9.23.1.13`	affected	—
`9.20.4.7`	affected	—
`9.22.2.13`	affected	—
`9.18.4.66`	affected	—
`9.20.4.10`	affected	—
`9.23.1.19`	affected	—
`9.16.4.85`	affected	—
`9.22.2.14`	affected	—
`9.18.4.67`	affected	—
`9.18.4.68`	affected	—
`9.23.1.22`	affected	—
`9.20.4.14`	affected	—
`9.22.2.20`	affected	—

Cisco

Cisco Secure Firewall Threat Defense (FTD) Software

unknown

Version	Status	Constraints
`7.0.0`	affected	—
`7.0.0.1`	affected	—
`7.0.1`	affected	—
`7.0.1.1`	affected	—
`7.0.2`	affected	—
`7.2.0`	affected	—
`7.0.2.1`	affected	—
`7.0.3`	affected	—
`7.2.0.1`	affected	—
`7.0.4`	affected	—
`7.2.1`	affected	—
`7.0.5`	affected	—
`7.3.0`	affected	—
`7.2.2`	affected	—
`7.2.3`	affected	—
`7.3.1`	affected	—
`7.2.4`	affected	—
`7.0.6`	affected	—
`7.2.5`	affected	—
`7.2.4.1`	affected	—
`7.3.1.1`	affected	—
`7.4.0`	affected	—
`7.0.6.1`	affected	—
`7.2.5.1`	affected	—
`7.4.1`	affected	—
`7.2.6`	affected	—
`7.0.6.2`	affected	—
`7.4.1.1`	affected	—
`7.2.7`	affected	—
`7.2.5.2`	affected	—
`7.3.1.2`	affected	—
`7.2.8`	affected	—
`7.6.0`	affected	—
`7.4.2`	affected	—
`7.2.8.1`	affected	—
`7.0.6.3`	affected	—
`7.4.2.1`	affected	—
`7.2.9`	affected	—
`7.0.7`	affected	—
`7.7.0`	affected	—
`7.4.2.2`	affected	—
`7.2.10`	affected	—
`7.6.1`	affected	—
`7.4.2.3`	affected	—
`7.0.8`	affected	—
`7.6.2`	affected	—
`7.7.10`	affected	—
`7.7.11`	affected	—
`7.0.8.1`	affected	—
`7.6.2.1`	affected	—
`7.7.10.1`	affected	—
`7.4.2.4`	affected	—
`7.2.10.2`	affected	—
`7.4.3`	affected	—
`7.6.4`	affected	—
`7.4.4`	affected	—

No data.

Vendor Product Versions

Cisco

Adaptive Security Appliance Software

Version	Status	Scheme	Platform
`9.16.1`	affected	semver	—
`9.16.1.28`	affected	generic	—
`9.16.2`	affected	semver	—
`9.16.2.3`	affected	generic	—
`9.16.2.7`	affected	generic	—
`9.16.2.11`	affected	generic	—
`9.16.2.13`	affected	generic	—
`9.16.2.14`	affected	generic	—
`9.16.3.3`	affected	generic	—
`9.16.3`	affected	semver	—
`9.16.3.14`	affected	generic	—
`9.18.1`	affected	semver	—
`9.16.3.15`	affected	generic	—
`9.18.1.3`	affected	generic	—
`9.18.2`	affected	semver	—
`9.16.3.19`	affected	generic	—
`9.16.3.23`	affected	generic	—
`9.18.2.5`	affected	generic	—
`9.16.4`	affected	semver	—
`9.18.2.7`	affected	generic	—
`9.19.1`	affected	semver	—
`9.16.4.9`	affected	generic	—
`9.18.2.8`	affected	generic	—
`9.16.4.14`	affected	generic	—
`9.18.3`	affected	semver	—
`9.19.1.5`	affected	generic	—
`9.16.4.18`	affected	generic	—
`9.19.1.9`	affected	generic	—
`9.18.3.39`	affected	generic	—
`9.16.4.19`	affected	generic	—
`9.19.1.12`	affected	generic	—
`9.18.3.46`	affected	generic	—
`9.16.4.27`	affected	generic	—
`9.19.1.18`	affected	generic	—
`9.18.3.53`	affected	generic	—
`9.18.3.55`	affected	generic	—
`9.16.4.38`	affected	generic	—
`9.16.4.39`	affected	generic	—
`9.18.3.56`	affected	generic	—
`9.20.1`	affected	semver	—
`9.16.4.42`	affected	generic	—
`9.19.1.22`	affected	generic	—
`9.18.4`	affected	semver	—
`9.20.1.5`	affected	generic	—
`9.18.4.5`	affected	generic	—
`9.19.1.24`	affected	generic	—
`9.16.4.48`	affected	generic	—
`9.18.4.8`	affected	generic	—
`9.20.2`	affected	semver	—
`9.19.1.27`	affected	generic	—
`9.16.4.55`	affected	generic	—
`9.18.4.22`	affected	generic	—
`9.20.2.10`	affected	generic	—
`9.16.4.57`	affected	generic	—
`9.19.1.28`	affected	generic	—
`9.18.4.24`	affected	generic	—
`9.20.2.21`	affected	generic	—
`9.16.4.61`	affected	generic	—
`9.19.1.31`	affected	generic	—
`9.18.4.29`	affected	generic	—
`9.20.2.22`	affected	generic	—
`9.16.4.62`	affected	generic	—
`9.18.4.34`	affected	generic	—
`9.20.3`	affected	semver	—
`9.16.4.67`	affected	generic	—
`9.16.4.70`	affected	generic	—
`9.18.4.40`	affected	generic	—
`9.23.1`	affected	semver	—
`9.22.1.1`	affected	generic	—
`9.16.4.71`	affected	generic	—
`9.20.3.4`	affected	generic	—
`9.18.4.47`	affected	generic	—
`9.20.3.7`	affected	generic	—
`9.19.1.37`	affected	generic	—
`9.16.4.76`	affected	generic	—
`9.20.3.9`	affected	generic	—
`9.19.1.38`	affected	generic	—
`9.18.4.50`	affected	generic	—
`9.22.1.3`	affected	generic	—
`9.20.3.10`	affected	generic	—
`9.22.1.2`	affected	generic	—
`9.18.4.52`	affected	generic	—
`9.20.3.13`	affected	generic	—
`9.22.1.6`	affected	generic	—
`9.18.4.53`	affected	generic	—
`9.16.4.82`	affected	generic	—
`9.22.2`	affected	semver	—
`9.20.3.16`	affected	generic	—
`9.19.1.42`	affected	generic	—
`9.18.4.57`	affected	generic	—
`9.16.4.84`	affected	generic	—
`9.23.1.3`	affected	generic	—
`9.20.3.20`	affected	generic	—
`9.22.2.4`	affected	generic	—
`9.23.1.7`	affected	generic	—
`9.20.4`	affected	semver	—
`9.22.2.9`	affected	generic	—
`9.23.1.13`	affected	generic	—
`9.20.4.7`	affected	generic	—
`9.22.2.13`	affected	generic	—
`9.18.4.66`	affected	generic	—
`9.20.4.10`	affected	generic	—
`9.23.1.19`	affected	generic	—
`9.16.4.85`	affected	generic	—
`9.22.2.14`	affected	generic	—
`9.18.4.67`	affected	generic	—
`9.18.4.68`	affected	generic	—
`9.23.1.22`	affected	generic	—
`9.20.4.14`	affected	generic	—
`9.22.2.20`	affected	generic	—

Cisco

Cisco Secure Firewall Threat Defense (ftd) Software

Version	Status	Scheme	Platform
`7.0.0`	affected	semver	—
`7.0.0.1`	affected	generic	—
`7.0.1`	affected	semver	—
`7.0.1.1`	affected	generic	—
`7.0.2`	affected	semver	—
`7.2.0`	affected	semver	—
`7.0.2.1`	affected	generic	—
`7.0.3`	affected	semver	—
`7.2.0.1`	affected	generic	—
`7.0.4`	affected	semver	—
`7.2.1`	affected	semver	—
`7.0.5`	affected	semver	—
`7.3.0`	affected	semver	—
`7.2.2`	affected	semver	—
`7.2.3`	affected	semver	—
`7.3.1`	affected	semver	—
`7.2.4`	affected	semver	—
`7.0.6`	affected	semver	—
`7.2.5`	affected	semver	—
`7.2.4.1`	affected	generic	—
`7.3.1.1`	affected	semver	—
`7.4.0`	affected	semver	—
`7.0.6.1`	affected	generic	—
`7.2.5.1`	affected	generic	—
`7.4.1`	affected	semver	—
`7.2.6`	affected	semver	—
`7.0.6.2`	affected	generic	—
`7.4.1.1`	affected	semver	—
`7.2.7`	affected	semver	—
`7.2.5.2`	affected	generic	—
`7.3.1.2`	affected	semver	—
`7.2.8`	affected	semver	—
`7.6.0`	affected	semver	—
`7.4.2`	affected	semver	—
`7.2.8.1`	affected	generic	—
`7.0.6.3`	affected	generic	—
`7.4.2.1`	affected	generic	—
`7.2.9`	affected	semver	—
`7.0.7`	affected	semver	—
`7.7.0`	affected	semver	—
`7.4.2.2`	affected	generic	—
`7.2.10`	affected	semver	—
`7.6.1`	affected	semver	—
`7.4.2.3`	affected	generic	—
`7.0.8`	affected	semver	—
`7.6.2`	affected	semver	—
`7.7.10`	affected	semver	—
`7.7.11`	affected	semver	—
`7.0.8.1`	affected	generic	—
`7.6.2.1`	affected	generic	—
`7.7.10.1`	affected	generic	—
`7.4.2.4`	affected	generic	—
`7.2.10.2`	affected	semver	—
`7.4.3`	affected	semver	—
`7.6.4`	affected	semver	—
`7.4.4`	affected	semver	—

Cisco

Secure Firewall Threat Defense

Version	Status	Scheme	Platform
`7.0.0`	affected	semver	—
`7.0.0.1`	affected	generic	—
`7.0.1`	affected	semver	—
`7.0.1.1`	affected	generic	—
`7.0.2`	affected	semver	—
`7.2.0`	affected	semver	—
`7.0.2.1`	affected	generic	—
`7.0.3`	affected	semver	—
`7.2.0.1`	affected	generic	—
`7.0.4`	affected	semver	—
`7.2.1`	affected	semver	—
`7.0.5`	affected	semver	—
`7.3.0`	affected	semver	—
`7.2.2`	affected	semver	—
`7.2.3`	affected	semver	—
`7.3.1`	affected	semver	—
`7.2.4`	affected	semver	—
`7.0.6`	affected	semver	—
`7.2.5`	affected	semver	—
`7.2.4.1`	affected	generic	—
`7.3.1.1`	affected	semver	—
`7.4.0`	affected	semver	—
`7.0.6.1`	affected	generic	—
`7.2.5.1`	affected	generic	—
`7.4.1`	affected	semver	—
`7.2.6`	affected	semver	—
`7.0.6.2`	affected	generic	—
`7.4.1.1`	affected	semver	—
`7.2.7`	affected	semver	—
`7.2.5.2`	affected	generic	—
`7.3.1.2`	affected	semver	—
`7.2.8`	affected	semver	—
`7.6.0`	affected	semver	—
`7.4.2`	affected	semver	—
`7.2.8.1`	affected	generic	—
`7.0.6.3`	affected	generic	—
`7.4.2.1`	affected	generic	—
`7.2.9`	affected	semver	—
`7.0.7`	affected	semver	—
`7.7.0`	affected	semver	—
`7.4.2.2`	affected	generic	—
`7.2.10`	affected	semver	—
`7.6.1`	affected	semver	—
`7.4.2.3`	affected	generic	—
`7.0.8`	affected	semver	—
`7.6.2`	affected	semver	—
`7.7.10`	affected	semver	—
`7.7.11`	affected	semver	—
`7.0.8.1`	affected	generic	—
`7.6.2.1`	affected	generic	—
`7.7.10.1`	affected	generic	—
`7.4.2.4`	affected	generic	—
`7.2.10.2`	affected	semver	—
`7.4.3`	affected	semver	—
`7.6.4`	affected	semver	—
`7.4.4`	affected	semver	—

Remediation

No solution or workaround provided in the CVE record

Tracking

Advisories

No advisories available

Metrics

No CVSS v4.0

Attack Vector Network

Attack Complexity Low

Privileges Required None

Scope Changed

Confidentiality Impact None

Integrity Impact None

Availability Impact High

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

Exploit prediction score: < 1% (0.573% probability within 30 days)

Exploitation none

Automatable yes

Technical Impact partial

References

Link	Providers
https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asa-ftd-logging-dos-ZXXNesfN

History

Nov 10, 2026 11:00 PM First appearance in the feed. Affected vendors updated View changes

Type	Values Removed	Values Added
First Time appeared		Cisco Cisco adaptive Security Appliance Software Cisco cisco Secure Firewall Threat Defense (ftd) Software Cisco secure Firewall Threat Defense
Vendors & Products		Cisco Cisco adaptive Security Appliance Software Cisco cisco Secure Firewall Threat Defense (ftd) Software Cisco secure Firewall Threat Defense

Sep 18, 2026 9:30 PM Scoring metrics updated View changes

Type	Values Removed	Values Added
Metrics		ssvc `{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}`

Sep 16, 2026 8:30 PM Description updated. Title updated. Weaknesses updated. Added references. Scoring metrics updated View changes

Type	Values Removed	Values Added
Description		A vulnerability in the system rate-limiting process for syslog message 419002 of Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Cisco Secure Firewall Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause high CPU utilization on an affected device, resulting in a denial of service (DoS) condition. This vulnerability is due to improper rate limiting for syslog message 419002. An attacker could exploit this vulnerability by sending a flood of TCP synchronization (SYN) packets to an affected device. A successful exploit could allow the attacker to cause high CPU utilization, resulting in performance degradation.
Title		Cisco Secure Firewall Adaptive Security Appliance Software and Secure Firewall Threat Defense Software Logging Denial of Service
Weaknesses		CWE-835
References		https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asa-ftd-logging-dos-ZXXNesfN
Metrics		cvssV3_1 `{'score': 8.6, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H'}`