CVE-2026-20154 PUBLISHED

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

Assigner: cisco
Reserved: 08.10.2025 Published: 16.09.2026 Updated: 16.09.2026

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. 

Metrics

CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
CVSS Score: 8.6

Product Status

Vendor Cisco
Product Cisco Secure Firewall Adaptive Security Appliance (ASA) Software
Versions Default: unknown
  • Version 9.16.1 is affected
  • Version 9.16.1.28 is affected
  • Version 9.16.2 is affected
  • Version 9.16.2.3 is affected
  • Version 9.16.2.7 is affected
  • Version 9.16.2.11 is affected
  • Version 9.16.2.13 is affected
  • Version 9.16.2.14 is affected
  • Version 9.16.3.3 is affected
  • Version 9.16.3 is affected
  • Version 9.16.3.14 is affected
  • Version 9.18.1 is affected
  • Version 9.16.3.15 is affected
  • Version 9.18.1.3 is affected
  • Version 9.18.2 is affected
  • Version 9.16.3.19 is affected
  • Version 9.16.3.23 is affected
  • Version 9.18.2.5 is affected
  • Version 9.16.4 is affected
  • Version 9.18.2.7 is affected
  • Version 9.19.1 is affected
  • Version 9.16.4.9 is affected
  • Version 9.18.2.8 is affected
  • Version 9.16.4.14 is affected
  • Version 9.18.3 is affected
  • Version 9.19.1.5 is affected
  • Version 9.16.4.18 is affected
  • Version 9.19.1.9 is affected
  • Version 9.18.3.39 is affected
  • Version 9.16.4.19 is affected
  • Version 9.19.1.12 is affected
  • Version 9.18.3.46 is affected
  • Version 9.16.4.27 is affected
  • Version 9.19.1.18 is affected
  • Version 9.18.3.53 is affected
  • Version 9.18.3.55 is affected
  • Version 9.16.4.38 is affected
  • Version 9.16.4.39 is affected
  • Version 9.18.3.56 is affected
  • Version 9.20.1 is affected
  • Version 9.16.4.42 is affected
  • Version 9.19.1.22 is affected
  • Version 9.18.4 is affected
  • Version 9.20.1.5 is affected
  • Version 9.18.4.5 is affected
  • Version 9.19.1.24 is affected
  • Version 9.16.4.48 is affected
  • Version 9.18.4.8 is affected
  • Version 9.20.2 is affected
  • Version 9.19.1.27 is affected
  • Version 9.16.4.55 is affected
  • Version 9.18.4.22 is affected
  • Version 9.20.2.10 is affected
  • Version 9.16.4.57 is affected
  • Version 9.19.1.28 is affected
  • Version 9.18.4.24 is affected
  • Version 9.20.2.21 is affected
  • Version 9.16.4.61 is affected
  • Version 9.19.1.31 is affected
  • Version 9.18.4.29 is affected
  • Version 9.20.2.22 is affected
  • Version 9.16.4.62 is affected
  • Version 9.18.4.34 is affected
  • Version 9.20.3 is affected
  • Version 9.16.4.67 is affected
  • Version 9.16.4.70 is affected
  • Version 9.18.4.40 is affected
  • Version 9.23.1 is affected
  • Version 9.22.1.1 is affected
  • Version 9.16.4.71 is affected
  • Version 9.20.3.4 is affected
  • Version 9.18.4.47 is affected
  • Version 9.20.3.7 is affected
  • Version 9.19.1.37 is affected
  • Version 9.16.4.76 is affected
  • Version 9.20.3.9 is affected
  • Version 9.19.1.38 is affected
  • Version 9.18.4.50 is affected
  • Version 9.22.1.3 is affected
  • Version 9.20.3.10 is affected
  • Version 9.22.1.2 is affected
  • Version 9.18.4.52 is affected
  • Version 9.20.3.13 is affected
  • Version 9.22.1.6 is affected
  • Version 9.18.4.53 is affected
  • Version 9.16.4.82 is affected
  • Version 9.22.2 is affected
  • Version 9.20.3.16 is affected
  • Version 9.19.1.42 is affected
  • Version 9.18.4.57 is affected
  • Version 9.16.4.84 is affected
  • Version 9.23.1.3 is affected
  • Version 9.20.3.20 is affected
  • Version 9.22.2.4 is affected
  • Version 9.23.1.7 is affected
  • Version 9.20.4 is affected
  • Version 9.22.2.9 is affected
  • Version 9.23.1.13 is affected
  • Version 9.20.4.7 is affected
  • Version 9.22.2.13 is affected
  • Version 9.18.4.66 is affected
  • Version 9.20.4.10 is affected
  • Version 9.23.1.19 is affected
  • Version 9.16.4.85 is affected
  • Version 9.22.2.14 is affected
  • Version 9.18.4.67 is affected
  • Version 9.18.4.68 is affected
  • Version 9.23.1.22 is affected
  • Version 9.20.4.14 is affected
  • Version 9.22.2.20 is affected
Vendor Cisco
Product Cisco Secure Firewall Threat Defense (FTD) Software
Versions Default: unknown
  • Version 7.0.0 is affected
  • Version 7.0.0.1 is affected
  • Version 7.0.1 is affected
  • Version 7.0.1.1 is affected
  • Version 7.0.2 is affected
  • Version 7.2.0 is affected
  • Version 7.0.2.1 is affected
  • Version 7.0.3 is affected
  • Version 7.2.0.1 is affected
  • Version 7.0.4 is affected
  • Version 7.2.1 is affected
  • Version 7.0.5 is affected
  • Version 7.3.0 is affected
  • Version 7.2.2 is affected
  • Version 7.2.3 is affected
  • Version 7.3.1 is affected
  • Version 7.2.4 is affected
  • Version 7.0.6 is affected
  • Version 7.2.5 is affected
  • Version 7.2.4.1 is affected
  • Version 7.3.1.1 is affected
  • Version 7.4.0 is affected
  • Version 7.0.6.1 is affected
  • Version 7.2.5.1 is affected
  • Version 7.4.1 is affected
  • Version 7.2.6 is affected
  • Version 7.0.6.2 is affected
  • Version 7.4.1.1 is affected
  • Version 7.2.7 is affected
  • Version 7.2.5.2 is affected
  • Version 7.3.1.2 is affected
  • Version 7.2.8 is affected
  • Version 7.6.0 is affected
  • Version 7.4.2 is affected
  • Version 7.2.8.1 is affected
  • Version 7.0.6.3 is affected
  • Version 7.4.2.1 is affected
  • Version 7.2.9 is affected
  • Version 7.0.7 is affected
  • Version 7.7.0 is affected
  • Version 7.4.2.2 is affected
  • Version 7.2.10 is affected
  • Version 7.6.1 is affected
  • Version 7.4.2.3 is affected
  • Version 7.0.8 is affected
  • Version 7.6.2 is affected
  • Version 7.7.10 is affected
  • Version 7.7.11 is affected
  • Version 7.0.8.1 is affected
  • Version 7.6.2.1 is affected
  • Version 7.7.10.1 is affected
  • Version 7.4.2.4 is affected
  • Version 7.2.10.2 is affected
  • Version 7.4.3 is affected
  • Version 7.6.4 is affected
  • Version 7.4.4 is affected

Exploits

The Cisco Product Security Incident Response Team (PSIRT) is not aware of any public announcements or malicious use of the vulnerability that is described in this advisory.

References

Problem Types

  • Loop with Unreachable Exit Condition ('Infinite Loop') cwe