CVE-2026-20100A vulnerability in the LUA interperter of the Remote Access SSL VPN feature of Cisco Secure Firewall Adaptive Security Appliance (ASA)…

Description

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 with a valid VPN connection to cause the device to reload unexpectedly, resulting in a denial of service (DoS) condition. This does not affect the management or MUS interfaces. This vulnerability is due to trusting user input without validation in the LUA interprerter. An attacker could exploit this vulnerability by sending crafted HTTP packets to the Remote Access SSL VPN server. A successful exploit could allow the attacker to cause the device to reload, resulting in a DoS condition.

Timeline

Scores

EPSS (exploitation in 30 days)

0.33% · top 74% of all CVEs (12 Nov 2026)

CISA SSVC

Exploitation: none · Automatable: no · Technical impact: partial

The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.7.

Affected products

• Cisco · Cisco Secure Firewall Adaptive Security Appliance (ASA) Software

  • affected 9.12.1
  • affected 9.12.1.2
  • affected 9.12.1.3
  • affected 9.12.2
  • affected 9.12.2.4
  • affected 9.12.2.5
  • affected 9.12.2.9
  • affected 9.12.3
  • affected 9.12.3.2
  • affected 9.12.3.7
  • affected 9.12.4
  • affected 9.12.3.12
  • affected 9.12.3.9
  • affected 9.12.2.1
  • affected 9.12.4.2
  • affected 9.12.4.4
  • affected 9.12.4.7
  • affected 9.12.4.10
  • affected 9.12.4.13
  • affected 9.12.4.8
  • affected 9.12.4.18
  • affected 9.12.4.24
  • affected 9.12.4.26
  • affected 9.12.4.29
  • affected 9.12.4.30
  • affected 9.12.4.35
  • affected 9.12.4.37
  • affected 9.12.4.38
  • affected 9.12.4.39
  • affected 9.12.4.40
  • affected 9.12.4.41
  • affected 9.12.4.47
  • affected 9.12.4.48
  • affected 9.12.4.50
  • affected 9.12.4.52
  • affected 9.12.4.54
  • affected 9.12.4.55
  • affected 9.12.4.56
  • affected 9.12.4.58
  • affected 9.12.4.62
  • and 107 more

• Cisco · Cisco Secure Firewall Threat Defense (FTD) Software

  • affected 6.4.0
  • affected 6.4.0.1
  • affected 6.4.0.3
  • affected 6.4.0.2
  • affected 6.4.0.4
  • affected 6.4.0.5
  • affected 6.4.0.6
  • affected 6.4.0.7
  • affected 6.4.0.8
  • affected 6.4.0.9
  • affected 6.4.0.10
  • affected 6.4.0.11
  • affected 6.4.0.12
  • affected 6.4.0.13
  • affected 6.4.0.14
  • affected 6.4.0.15
  • affected 6.4.0.16
  • affected 6.4.0.17
  • affected 6.4.0.18
  • affected 7.0.0
  • affected 7.0.0.1
  • affected 7.0.1
  • affected 7.0.1.1
  • affected 7.0.2
  • affected 7.0.2.1
  • affected 7.0.3
  • affected 7.0.4
  • affected 7.0.5
  • affected 7.0.6
  • affected 7.0.6.1
  • affected 7.0.6.2
  • affected 7.0.6.3
  • affected 7.0.7
  • affected 7.0.8
  • affected 7.0.8.1
  • affected 7.1.0
  • affected 7.1.0.1
  • affected 7.1.0.2
  • affected 7.1.0.3
  • affected 7.2.0
  • and 35 more

What to do

Exploitation: The Cisco Product Security Incident Response Team (PSIRT) is not aware of any public announcements or malicious use of the vulnerabilities that are described in this advisory.

Sources

The same CVE in the primary databases and aggregators, to check against.

• CVE.org record (opens in a new tab)
• CVE List JSON (GitHub) (opens in a new tab)
• NVD (opens in a new tab)
• FIRST EPSS (opens in a new tab)
• EUVD EUVD-2026-9439 (opens in a new tab)
• OSV.dev (opens in a new tab)
• GitHub Advisories (opens in a new tab)
• CIRCL Vulnerability-Lookup (opens in a new tab)

Badge for a README or a ticket

[![CVE-2026-20100](https://cveledger.app/badge/CVE-2026-20100.svg)](https://cveledger.app/cve/CVE-2026-20100)

Record last updated 5 Mar 2026, 15:34 UTC.