Buffer overflow in Cisco Adaptive_security_appliance_software
CVE-2026-20100
A vulnerability in the LUA interperter of the Remote Access SSL VPN feature of Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Secure Firewall Threat Defense (FTD) Software could allow an authenticated, remote attacker…
Vulnerability class: Buffer Overflow
EPSS: 0.001 (30.1th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 7.7 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H.
Affected products
- Cisco Adaptive_security_appliance_software — versions 9.12.1, 9.12.1.2, 9.12.1.3
- Cisco Secure Firewall Adaptive Security Appliance (Asa) Software — versions 9.12.1, 9.12.1.2, 9.12.1.3
- Cisco Secure Firewall Threat Defense (Ftd) Software — versions 6.4.0, 6.4.0.1, 6.4.0.3
- Cisco Firepower_threat_defense — versions 6.4.0, 6.4.0.1, 6.4.0.2
Weakness classification (CWE)
References
- cisco-sa-asaftd-vpn-m9sx6MbC (Vendor Advisory)
Frequently asked questions
- What is CVE-2026-20100?
- CVE-2026-20100 is a high-severity vulnerability in Cisco Adaptive_security_appliance_software, classified under Buffer Copy without Checking Size of Input (Classic Buffer Overflow). CVSS score: 7.7/10. Published 2026-03-04.
- How severe is CVE-2026-20100?
- High severity. CVSS v3 base score is 7.7 out of 10.