Answer in brief
CVE-2026-20154 records a Unknown severity vulnerability in Cisco Secure Firewall Adaptive Security Appliance Software and Secure Firewall Threat Defense Software Logging Denial of Service. The current sources do not mark it as known exploited. The current feed maps Cisco/Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (generic), Cisco/Cisco Secure Firewall Threat Defense (FTD) Software (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Cisco/Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (generic), Cisco/Cisco Secure Firewall Threat Defense (FTD) Software (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Cisco/Cisco Secure Firewall Adaptive Security Appliance (ASA) Softwaregeneric | 9.16.1 || 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 || 9.16.3.3 || 9.16.3 || 9.16.3.14 || 9.18.1 || 9.16.3.15 || 9.18.1.3 || 9.18.2 || 9.16.3.19 || 9.16.3.23 || 9.18.2.5 || 9.16.4 || 9.18.2.7 || 9.19.1 || 9.16.4.9 || 9.18.2.8 || 9.16.4.14 || 9.18.3 || 9.19.1.5 || 9.16.4.18 || 9.19.1.9 || 9.18.3.39 || 9.16.4.19 || 9.19.1.12 || 9.18.3.46 || 9.16.4.27 || 9.19.1.18 || 9.18.3.53 || 9.18.3.55 || 9.16.4.38 || 9.16.4.39 || 9.18.3.56 || 9.20.1 || 9.16.4.42 || 9.19.1.22 || 9.18.4 || 9.20.1.5 || 9.18.4.5 || 9.19.1.24 || 9.16.4.48 || 9.18.4.8 || 9.20.2 || 9.19.1.27 || 9.16.4.55 || 9.18.4.22 || 9.20.2.10 || 9.16.4.57 || 9.19.1.28 || 9.18.4.24 || 9.20.2.21 || 9.16.4.61 || 9.19.1.31 || 9.18.4.29 || 9.20.2.22 || 9.16.4.62 || 9.18.4.34 || 9.20.3 || 9.16.4.67 || 9.16.4.70 || 9.18.4.40 || 9.23.1 || 9.22.1.1 || 9.16.4.71 || 9.20.3.4 || 9.18.4.47 || 9.20.3.7 || 9.19.1.37 || 9.16.4.76 || 9.20.3.9 || 9.19.1.38 || 9.18.4.50 || 9.22.1.3 || 9.20.3.10 || 9.22.1.2 || 9.18.4.52 || 9.20.3.13 || 9.22.1.6 || 9.18.4.53 || 9.16.4.82 || 9.22.2 || 9.20.3.16 || 9.19.1.42 || 9.18.4.57 || 9.16.4.84 || 9.23.1.3 || 9.20.3.20 || 9.22.2.4 || 9.23.1.7 || 9.20.4 || 9.22.2.9 || 9.23.1.13 || 9.20.4.7 || 9.22.2.13 || 9.18.4.66 || 9.20.4.10 || 9.23.1.19 || 9.16.4.85 || 9.22.2.14 || 9.18.4.67 || 9.18.4.68 || 9.23.1.22 || 9.20.4.14 || 9.22.2.20 | Not reported |
| Cisco/Cisco Secure Firewall Threat Defense (FTD) Softwaregeneric | 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 || 7.2.0.1 || 7.0.4 || 7.2.1 || 7.0.5 || 7.3.0 || 7.2.2 || 7.2.3 || 7.3.1 || 7.2.4 || 7.0.6 || 7.2.5 || 7.2.4.1 || 7.3.1.1 || 7.4.0 || 7.0.6.1 || 7.2.5.1 || 7.4.1 || 7.2.6 || 7.0.6.2 || 7.4.1.1 || 7.2.7 || 7.2.5.2 || 7.3.1.2 || 7.2.8 || 7.6.0 || 7.4.2 || 7.2.8.1 || 7.0.6.3 || 7.4.2.1 || 7.2.9 || 7.0.7 || 7.7.0 || 7.4.2.2 || 7.2.10 || 7.6.1 || 7.4.2.3 || 7.0.8 || 7.6.2 || 7.7.10 || 7.7.11 || 7.0.8.1 || 7.6.2.1 || 7.7.10.1 || 7.4.2.4 || 7.2.10.2 || 7.4.3 || 7.6.4 || 7.4.4 | Not reported |
Published upstream
Sep 16, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Sep 16, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Sep 16, 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.
Quoted source text, attributed separately from HOL analysis.