CVE-2026-20154

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. 

CVSS v3 8.6 HIGH

8.6^/10

CVSS v3 : HIGH

Vector :

Exploitability : 3.9 / Impact : 4.0

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact HIGH

Scope CHANGED

References

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

Configurations

No configuration.

History

16 Sep 2026, 21:17

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-09-16 21:17

Updated : 2026-09-18 15:17

NVD link : CVE-2026-20154

Mitre link : CVE-2026-20154

CVE.ORG link : CVE-2026-20154

JSON object : View

Products Affected

No product.

CWE

CWE-835

Loop with Unreachable Exit Condition ('Infinite Loop')

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"affected", "version": "9.18.4"}, {"status": "affected", "version": "9.20.1.5"}, {"status": "affected", "version": "9.18.4.5"}, {"status": "affected", "version": "9.19.1.24"}, {"status": "affected", "version": "9.16.4.48"}, {"status": "affected", "version": "9.18.4.8"}, {"status": "affected", "version": "9.20.2"}, {"status": "affected", "version": "9.19.1.27"}, {"status": "affected", "version": "9.16.4.55"}, {"status": "affected", "version": "9.18.4.22"}, {"status": "affected", "version": "9.20.2.10"}, {"status": "affected", "version": "9.16.4.57"}, {"status": "affected", "version": "9.19.1.28"}, {"status": "affected", "version": "9.18.4.24"}, {"status": "affected", "version": "9.20.2.21"}, {"status": "affected", "version": "9.16.4.61"}, {"status": "affected", "version": "9.19.1.31"}, {"status": "affected", "version": "9.18.4.29"}, {"status": "affected", "version": "9.20.2.22"}, {"status": "affected", "version": "9.16.4.62"}, {"status": "affected", "version": "9.18.4.34"}, {"status": "affected", "version": "9.20.3"}, {"status": "affected", "version": "9.16.4.67"}, {"status": "affected", "version": "9.16.4.70"}, {"status": "affected", "version": "9.18.4.40"}, {"status": "affected", "version": "9.23.1"}, {"status": "affected", "version": "9.22.1.1"}, {"status": "affected", "version": "9.16.4.71"}, {"status": "affected", "version": "9.20.3.4"}, {"status": "affected", "version": "9.18.4.47"}, {"status": "affected", "version": "9.20.3.7"}, {"status": "affected", "version": "9.19.1.37"}, {"status": "affected", "version": "9.16.4.76"}, {"status": "affected", "version": "9.20.3.9"}, {"status": "affected", "version": "9.19.1.38"}, {"status": "affected", "version": "9.18.4.50"}, {"status": "affected", "version": "9.22.1.3"}, {"status": "affected", "version": "9.20.3.10"}, {"status": "affected", "version": "9.22.1.2"}, {"status": "affected", "version": "9.18.4.52"}, {"status": "affected", "version": "9.20.3.13"}, {"status": "affected", "version": "9.22.1.6"}, {"status": 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"affected", "version": "7.2.3"}, {"status": "affected", "version": "7.3.1"}, {"status": "affected", "version": "7.2.4"}, {"status": "affected", "version": "7.0.6"}, {"status": "affected", "version": "7.2.5"}, {"status": "affected", "version": "7.2.4.1"}, {"status": "affected", "version": "7.3.1.1"}, {"status": "affected", "version": "7.4.0"}, {"status": "affected", "version": "7.0.6.1"}, {"status": "affected", "version": "7.2.5.1"}, {"status": "affected", "version": "7.4.1"}, {"status": "affected", "version": "7.2.6"}, {"status": "affected", "version": "7.0.6.2"}, {"status": "affected", "version": "7.4.1.1"}, {"status": "affected", "version": "7.2.7"}, {"status": "affected", "version": "7.2.5.2"}, {"status": "affected", "version": "7.3.1.2"}, {"status": "affected", "version": "7.2.8"}, {"status": "affected", "version": "7.6.0"}, {"status": "affected", "version": "7.4.2"}, {"status": "affected", "version": "7.2.8.1"}, {"status": "affected", "version": "7.0.6.3"}, {"status": "affected", "version": "7.4.2.1"}, {"status": "affected", "version": "7.2.9"}, {"status": "affected", "version": "7.0.7"}, {"status": "affected", "version": "7.7.0"}, {"status": "affected", "version": "7.4.2.2"}, {"status": "affected", "version": "7.2.10"}, {"status": "affected", "version": "7.6.1"}, {"status": "affected", "version": "7.4.2.3"}, {"status": "affected", "version": "7.0.8"}, {"status": "affected", "version": "7.6.2"}, {"status": "affected", "version": "7.7.10"}, {"status": "affected", "version": "7.7.11"}, {"status": "affected", "version": "7.0.8.1"}, {"status": "affected", "version": "7.6.2.1"}, {"status": "affected", "version": "7.7.10.1"}, {"status": "affected", "version": "7.4.2.4"}, {"status": "affected", "version": "7.2.10.2"}, {"status": "affected", "version": "7.4.3"}, {"status": "affected", "version": "7.6.4"}, {"status": "affected", "version": "7.4.4"}], "defaultStatus": "unknown"}]}], "published": "2026-09-16T21:17:07.723", "references": [{"url": "https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asa-ftd-logging-dos-ZXXNesfN", "source": "psirt@cisco.com"}], "vulnStatus": "Awaiting Analysis", "weaknesses": [{"type": "Secondary", "source": "psirt@cisco.com", "description": [{"lang": "en", "value": "CWE-835"}]}], "descriptions": [{"lang": "en", "value": "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.\r\n\r\nThis 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. "}], "lastModified": "2026-09-18T15:17:06.753", "sourceIdentifier": "psirt@cisco.com"}