Cisco Patches Vulnerability in ASA and FTD Software
Cisco has issued patches for a vulnerability in its Secure Firewall ASA and FTD software, which is being actively exploited. The flaw allows unauthenticated remote attackers to cause a denial-of-service condition.
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What happened
Cisco released fixes for a vulnerability in its firewall software.
Who is affected
Secure Firewall ASA and Secure Firewall FTD software.
Exploited
Exploitation confirmed.
What to do
Upgrade to a fixed software release.
Cisco has released security updates to address a vulnerability in its Secure Firewall Adaptive Security Appliance (ASA) and Secure Firewall Threat Defense (FTD) software. The vulnerability, identified as CVE-2026-76418, has a CVSS score of 8.6.
The flaw is located in the Remote Access SSL VPN service and can be exploited by remote attackers without authentication. Successful exploitation may lead to an unexpected device restart, causing a denial-of-service (DoS) condition.
Cisco's product security team confirmed that the vulnerability has been exploited in the wild as of October 2026. However, specific details about the attacks or the threat actors involved have not been disclosed.
The issue stems from logic errors affecting tunnel groups configured with secondary authentication. Cisco has advised users to upgrade to a fixed software release to mitigate the vulnerability, as no workarounds are available.
This marks the second zero-day vulnerability in recent months affecting ASA and FTD software for DoS attacks, following the exploitation of CVE-2026-20349.
