CVE-2026-20154 json
Cisco Secure Firewall Adaptive Security Appliance Software and Secure Firewall Threat Defense Software Logging Denial of Service
published 2026-09-16 53 d ago modified 2026-09-18 51 d ago also EUVD-2026-81128
- cvss
- 8.6
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.6%
- EPSS 0.6% chance of exploitation in 30 days, percentile 47%
- public exploits
- 0
- none known
Summary
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.
CISA SSVC
- Exploitation
- none
- Automatable
- yes
- Technical impact
- partial
- Assessed
- 51 d ago
Exploit prediction
0.57% chance of exploitation in the next 30 days, higher than 47% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 8.6 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H |
Affected products
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software
- Cisco Cisco Secure Firewall Threat Defense (FTD) Software
Classification
- Weakness
-
- CWE-835 Loop with Unreachable Exit Condition
References
Sources
- CVE List CVE-2026-20154
- NVD CVE-2026-20154
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