# CVE-2026-20349

## Summary

- **CVE ID:** CVE-2026-20349
- **Severity:** HIGH
- **CVSS Score:** 8.6 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H)
- **CWE:** CWE-244
- **Published:** Aug 11, 2026
- **Last Modified:** Aug 12, 2026

## Description

A vulnerability in the Remote Access SSL VPN service for Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Cisco Secure Firewall Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause the device to reload unexpectedly, resulting in a denial of service (DoS) condition. 

This vulnerability is due to insufficient error checking when processing HTTP requests. An attacker could exploit this vulnerability by sending a crafted HTTP request to the Remote Access SSL VPN service on an affected device. A successful exploit could allow the attacker to cause the affected device to reload, resulting in a DoS condition.

## Affected Products

- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.16.1)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.16.1.28)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.16.2)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.16.2.3)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.16.2.7)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.16.2.11)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.16.2.13)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.16.2.14)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.16.3.3)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.16.3)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.16.3.14)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.18.1)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.16.3.15)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.18.1.3)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.18.2)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.16.3.19)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.16.3.23)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.18.2.5)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.16.4)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.18.2.7)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.19.1)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.16.4.9)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.18.2.8)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.16.4.14)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.18.3)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.19.1.5)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.19.1.9)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.18.3.39)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.16.4.19)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.19.1.12)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.18.3.46)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.16.4.27)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.19.1.18)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.18.3.53)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.18.3.55)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.16.4.38)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.16.4.39)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.18.3.56)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.20.1)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.16.4.42)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.19.1.22)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.18.4)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.20.1.5)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.18.4.5)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.19.1.24)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.16.4.48)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.18.4.8)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.20.2)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.19.1.27)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.16.4.55)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.18.4.22)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.20.2.10)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.16.4.57)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.19.1.28)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.18.4.24)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.20.2.21)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.16.4.61)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.19.1.31)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.18.4.29)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.20.2.22)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.16.4.62)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.18.4.34)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.20.3)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.16.4.67)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.16.4.70)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.18.4.40)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.23.1)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.22.1.1)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.16.4.71)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.20.3.4)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.18.4.47)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.20.3.7)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.19.1.37)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.16.4.76)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.20.3.9)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.19.1.38)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.18.4.50)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.22.1.3)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.20.3.10)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.22.1.2)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.18.4.52)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.20.3.13)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.22.1.6)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.18.4.53)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.16.4.82)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.22.2)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.20.3.16)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.19.1.42)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.18.4.57)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.16.4.84)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.23.1.3)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.20.3.20)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.22.2.4)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.23.1.7)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.20.4)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.22.2.9)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.23.1.13)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.20.4.7)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.22.2.13)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.18.4.66)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.20.4.10)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.23.1.19)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.16.4.85)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.22.2.14)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.18.4.67)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.24.1)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.18.4.68)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.23.1.22)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.20.4.14)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.22.2.20)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.18.4.71)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.20.4.19)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.23.1.26)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.16.4.89)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.22.2.32)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.18.4.76)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.22.3)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.24.1.5)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.20.4.22)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.24.1.9)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.20.4.28)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.22.3.5)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.16.4.92)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.18.4.135)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.23.1.195)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.20.4.30)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.24.1.155)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.23.1.32)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.24.1.11)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.20.4.34)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.18.4.82)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.18.4.90)
- Cisco — Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (9.20.4.46)
- Cisco — Cisco Secure Firewall Threat Defense (FTD) Software (7.0.0)
- Cisco — Cisco Secure Firewall Threat Defense (FTD) Software (7.0.0.1)
- Cisco — Cisco Secure Firewall Threat Defense (FTD) Software (7.0.1)
- Cisco — Cisco Secure Firewall Threat Defense (FTD) Software (7.0.1.1)
- Cisco — Cisco Secure Firewall Threat Defense (FTD) Software (7.0.2)
- Cisco — Cisco Secure Firewall Threat Defense (FTD) Software (7.2.0)
- Cisco — Cisco Secure Firewall Threat Defense (FTD) Software (7.0.2.1)
- Cisco — Cisco Secure Firewall Threat Defense (FTD) Software (7.0.3)
- Cisco — Cisco Secure Firewall Threat Defense (FTD) Software (7.2.0.1)
- Cisco — Cisco Secure Firewall Threat Defense (FTD) Software (7.0.4)
- Cisco — Cisco Secure Firewall Threat Defense (FTD) Software (7.2.1)
- Cisco — Cisco Secure Firewall Threat Defense (FTD) Software (7.0.5)
- Cisco — Cisco Secure Firewall Threat Defense (FTD) Software (7.3.0)
- Cisco — Cisco Secure Firewall Threat Defense (FTD) Software (7.2.2)
- Cisco — Cisco Secure Firewall Threat Defense (FTD) Software (7.2.3)
- Cisco — Cisco Secure Firewall Threat Defense (FTD) Software (7.3.1)
- Cisco — Cisco Secure Firewall Threat Defense (FTD) Software (7.2.4)
- Cisco — Cisco Secure Firewall Threat Defense (FTD) Software (7.0.6)
- Cisco — Cisco Secure Firewall Threat Defense (FTD) Software (7.2.5)
- Cisco — Cisco Secure Firewall Threat Defense (FTD) Software (7.2.4.1)
- Cisco — Cisco Secure Firewall Threat Defense (FTD) Software (7.3.1.1)
- Cisco — Cisco Secure Firewall Threat Defense (FTD) Software (7.4.0)
- Cisco — Cisco Secure Firewall Threat Defense (FTD) Software (7.0.6.1)
- Cisco — Cisco Secure Firewall Threat Defense (FTD) Software (7.2.5.1)
- Cisco — Cisco Secure Firewall Threat Defense (FTD) Software (7.4.1)
- Cisco — Cisco Secure Firewall Threat Defense (FTD) Software (7.2.6)
- Cisco — Cisco Secure Firewall Threat Defense (FTD) Software (7.0.6.2)
- Cisco — Cisco Secure Firewall Threat Defense (FTD) Software (7.4.1.1)
- Cisco — Cisco Secure Firewall Threat Defense (FTD) Software (7.2.7)
- Cisco — Cisco Secure Firewall Threat Defense (FTD) Software (7.2.5.2)
- Cisco — Cisco Secure Firewall Threat Defense (FTD) Software (7.3.1.2)
- Cisco — Cisco Secure Firewall Threat Defense (FTD) Software (7.2.8)
- Cisco — Cisco Secure Firewall Threat Defense (FTD) Software (7.6.0)
- Cisco — Cisco Secure Firewall Threat Defense (FTD) Software (7.4.2)
- Cisco — Cisco Secure Firewall Threat Defense (FTD) Software (7.2.8.1)
- Cisco — Cisco Secure Firewall Threat Defense (FTD) Software (7.0.6.3)
- Cisco — Cisco Secure Firewall Threat Defense (FTD) Software (7.4.2.1)
- Cisco — Cisco Secure Firewall Threat Defense (FTD) Software (7.2.9)
- Cisco — Cisco Secure Firewall Threat Defense (FTD) Software (7.0.7)
- Cisco — Cisco Secure Firewall Threat Defense (FTD) Software (7.7.0)
- Cisco — Cisco Secure Firewall Threat Defense (FTD) Software (7.4.2.2)
- Cisco — Cisco Secure Firewall Threat Defense (FTD) Software (7.2.10)
- Cisco — Cisco Secure Firewall Threat Defense (FTD) Software (7.6.1)
- Cisco — Cisco Secure Firewall Threat Defense (FTD) Software (7.4.2.3)
- Cisco — Cisco Secure Firewall Threat Defense (FTD) Software (7.0.8)
- Cisco — Cisco Secure Firewall Threat Defense (FTD) Software (7.6.2)
- Cisco — Cisco Secure Firewall Threat Defense (FTD) Software (7.7.10)
- Cisco — Cisco Secure Firewall Threat Defense (FTD) Software (7.7.11)
- Cisco — Cisco Secure Firewall Threat Defense (FTD) Software (7.0.8.1)
- Cisco — Cisco Secure Firewall Threat Defense (FTD) Software (7.6.2.1)
- Cisco — Cisco Secure Firewall Threat Defense (FTD) Software (7.7.10.1)
- Cisco — Cisco Secure Firewall Threat Defense (FTD) Software (7.4.2.4)
- Cisco — Cisco Secure Firewall Threat Defense (FTD) Software (7.2.10.2)
- Cisco — Cisco Secure Firewall Threat Defense (FTD) Software (7.4.3)
- Cisco — Cisco Secure Firewall Threat Defense (FTD) Software (7.6.4)
- Cisco — Cisco Secure Firewall Threat Defense (FTD) Software (10.0.0)
- Cisco — Cisco Secure Firewall Threat Defense (FTD) Software (7.4.4)
- Cisco — Cisco Secure Firewall Threat Defense (FTD) Software (7.0.9)
- Cisco — Cisco Secure Firewall Threat Defense (FTD) Software (7.2.11)
- Cisco — Cisco Secure Firewall Threat Defense (FTD) Software (7.4.7)
- Cisco — Cisco Secure Firewall Threat Defense (FTD) Software (7.4.8)
- Cisco — Cisco Secure Firewall Threat Defense (FTD) Software (7.2.12)
- Cisco — Cisco Secure Firewall Threat Defense (FTD) Software (7.7.13)
- Cisco — Cisco Secure Firewall Threat Defense (FTD) Software (10.0.2)

## References

- [CNA](https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asaftd-vpn-dos-dzv4mQFF)
- [CISA-ADP](https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-20349)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 2.21%
- **EPSS Percentile:** 81.6

## Known Exploited Vulnerabilities (KEV)

- **Date Added:** Aug 11, 2026
- **Due Date:** Aug 14, 2026

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-12._