Remote Access SSL VPN Vulnerability in Cisco Secure Firewall ASA and FTD Software
CVE-2026-20100

7.7HIGH

Key Information:

Vendor

Cisco
Status
Cisco Secure Firewall Adaptive Security Appliance (asa) Software
Cisco Secure Firewall Threat Defense (ftd) Software
Vendor
CVE Published:
4 March 2026

Badges

👾 Exploit Exists

What is CVE-2026-20100?

A flaw in the LUA interpreter of Cisco Secure Firewall ASA and FTD's Remote Access SSL VPN feature allows authenticated remote attackers to send specially crafted HTTP packets, causing the device to unexpectedly reload and leading to denial of service (DoS). This vulnerability arises from a lack of input validation, thereby enabling an attacker with a valid VPN session to exploit it. The attack does not compromise management or MUS interfaces.

Affected Version(s)

Cisco Secure Firewall Adaptive Security Appliance (ASA) Software 9.12.1

Cisco Secure Firewall Adaptive Security Appliance (ASA) Software 9.12.1.2

Cisco Secure Firewall Adaptive Security Appliance (ASA) Software 9.12.1.3

References

https://sec.cloudapps.cisco.com/security/center/content/C...

CVSS V3.1

Score:
7.7
Severity:
HIGH
Confidentiality:
None
Integrity:
None
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
Low
User Interaction:
None
Scope:
Changed

Timeline

  • 👾

    Exploit known to exist

  • Vulnerability published

  • Vulnerability Reserved

.