CVE-2026-20349

Analyzed

Published: 11 Aug 2026, 17:06

Last modified:12 Aug 2026, 04:00

Vulnerability Summary

Overall Risk (default)

medium

35/100

CVSS Score

8.6 HIGH

v3.1 (cve.org)

EPSS Score

0.87% LOW

1% probability -0.10%

KEV

Listed

CISA

1 listing

Ransomware

No reports

Public exploits

None found

Dark Web

Not detected

Timeline

11 Aug 2026, 17:06

Published

Vulnerability first disclosed

11 Aug 2026, 00:00

Added to CISA KEV

Cisco Secure Firewall Adaptive Security Appliance (ASA) and Secure Firewall Threat Defense (FTD) Heap Inspection Vulnerability

12 Aug 2026, 04:00

Last Modified

Vulnerability information updated

14 Aug 2026, 00:00

CISA Remediation Due

Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.

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.

CVSS Metrics

v3.1•HIGH•Score: 8.6CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H

EPSS Trends

Current EPSS score: 0.87%• Percentile: 56%

Techniques & Countermeasures

CWE-244•Improper Clearing of Heap Memory Before Release ('Heap Inspection')
Using realloc() to resize buffers that store sensitive information can leave the sensitive information exposed to attack, because it is not removed from memory.

Affected Systems

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