CVE-2026-76418

HIGH

A vulnerability in the Remote Access SSL VPN service 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 the device to reload unexpectedly, resulting in a denial of service (DoS) condition. This vulnerability is due to logic errors when secondary authentication is configured on a tunnel group. An attacker could exploit this vulnerability by sending a crafted request when connecting to the SSL remote access VPN. A successful exploit could allow the attacker to cause the affected device to reload, resulting in a DoS condition.

CVSS v3.1 Score

8.6
HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
CHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Published: 10/28/2026Modified: 10/29/2026

Related Intelligence (4)

CRITICALZero Day

New Cisco firewall zero-day being actively exploited

A high-severity flaw in the Remote Access SSL VPN service of Cisco Secure Firewall Adaptive Security Appliance (ASA) and Cisco Secure Firewall Threat Defense (FTD) is under active exploitation to crash vulnerable devices. The vulnerability, tracked as CVE-2026-76418 and rated 8.6 in severity, is due to logic errors when secondary authentication is configured on a tunnel group, Cisco said in its ad

CVE-2026-76418
CSO Online
CRITICALApt

Cisco Patches Actively Exploited ASA and FTD VPN Flaw That Can Crash Firewalls

Cisco has released patches to address a high-severity security flaw in Secure Firewall Adaptive Security Appliance (ASA) Software and Secure Firewall Threat Defense (FTD) Software that it said has been exploited in the wild. The vulnerability, tracked as CVE-2026-76418, is rated 8.6 on the CVSS scoring system. Successful exploitation could allow an unauthenticated, remote attacker to cause the

CVE-2026-76418
The Hacker News
CRITICALZero Day

Attackers Exploit Second Cisco Firewall VPN Zero-Day Since August

Cisco on Wednesday released fixes for an exploited vulnerability affecting its Secure Firewall Adaptive Security Appliance (ASA) and Secure Firewall Threat Defense (FTD) software. Tracked as CVE-2026-76418 and assigned a CVSS score of 8.6, the bug resides in the Remote Access SSL VPN service. Attackers can exploit it remotely, without authenticating, to force the device […] The post Attacker

CVE-2026-76418
SecurityWeek
HIGHVulnerability

CISA KEV: Cisco Secure Firewall ASA Software and Cisco Secure FTD Software — Cisco Secure Firewall ASA Software and Cisco Secure FTD Software Unchecked Return Value to NULL Pointer Dereference Vulnerability

Cisco Secure Firewall ASA Software and Cisco Secure FTD Software contains an unchecked return value to NULL pointer dereference vulnerability that could allow an unauthenticated, remote attacker to cause the device to reload unexpectedly, resulting in a denial of service (DoS) condition.

CVE-2026-76418Cisco Secure Firewall ASA Software and Cisco Secure FTD Software
CISA KEV

References (1)

https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asaftd-tunnel-dos-s6mgkb75