CVE-2026-76418: Cisco Secure Firewall ASA Software and Cisco Secure FTD Software (High, CVSS 8.6)
- CVSS
- 8.6 High (v3.1)
- EPSS
- 0.6% chance of exploitation in the next 30 days (higher than 47.3% of CVEs)
- Exploited in the wild
- Yes, on CISA’s KEV list since Oct 29, 2026
- Public exploit
- None reported in public exploit databases
- Weakness
- CWE-690
- Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H- Published
- Oct 28, 2026
- CISA fix-by date
- Nov 1, 2026 (for US federal agencies)
What it is
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.
Description from the National Vulnerability Database.
What to do
CISA: 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
Check whether you run Cisco Secure Firewall ASA Software and Cisco Secure FTD Software, then apply the vendor’s fix or mitigation from the advisories below. Because this flaw is exploited or has public exploit code, treat it as urgent and check for signs of compromise, not just the patch level.
ThreatRoundup coverage
Cisco Firewall VPN Bug Is Being Used to Knock ASA and FTD Offline
Sources: NVD, FIRST EPSS, CISA KEV, and public exploit databases (availability only). ThreatRoundup reports whether public exploit code exists but never links to it: fake proof-of-concepts that infect security researchers are common. This page updates automatically.