CVE-2026-20100

HIGHCVSS 7.7/10EPSS 0.28%

Last modified

CVE-2026-20100 is a high-severity vulnerability rated 7.7/10 on the CVSS scale. 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. EPSS estimates a 0.28% chance of exploitation in the next 30 days.

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.

Metrics

CVSS 3.1
7.7/10

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H

EPSS Probability
0.28%

19.9th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

VendorProductVersions
CiscoAdaptive Security Appliance Software9.12.1
CiscoAdaptive Security Appliance Software9.12.1.2
CiscoAdaptive Security Appliance Software9.12.1.3
CiscoAdaptive Security Appliance Software9.12.2
CiscoAdaptive Security Appliance Software9.12.2.1
CiscoAdaptive Security Appliance Software9.12.2.4
CiscoAdaptive Security Appliance Software9.12.2.5
CiscoAdaptive Security Appliance Software9.12.2.9
CiscoAdaptive Security Appliance Software9.12.3
CiscoAdaptive Security Appliance Software9.12.3.2
CiscoAdaptive Security Appliance Software9.12.3.7
CiscoAdaptive Security Appliance Software9.12.3.9
CiscoAdaptive Security Appliance Software9.12.3.12
CiscoAdaptive Security Appliance Software9.12.4
CiscoAdaptive Security Appliance Software9.12.4.2
CiscoAdaptive Security Appliance Software9.12.4.4
CiscoAdaptive Security Appliance Software9.12.4.7
CiscoAdaptive Security Appliance Software9.12.4.8
CiscoAdaptive Security Appliance Software9.12.4.10
CiscoAdaptive Security Appliance Software9.12.4.13
CiscoAdaptive Security Appliance Software9.12.4.18
CiscoAdaptive Security Appliance Software9.12.4.24
CiscoAdaptive Security Appliance Software9.12.4.26
CiscoAdaptive Security Appliance Software9.12.4.29
CiscoAdaptive Security Appliance Software9.12.4.30
CiscoAdaptive Security Appliance Software9.12.4.35
CiscoAdaptive Security Appliance Software9.12.4.37
CiscoAdaptive Security Appliance Software9.12.4.38
CiscoAdaptive Security Appliance Software9.12.4.39
CiscoAdaptive Security Appliance Software9.12.4.40
CiscoAdaptive Security Appliance Software9.12.4.41
CiscoAdaptive Security Appliance Software9.12.4.47
CiscoAdaptive Security Appliance Software9.12.4.48
CiscoAdaptive Security Appliance Software9.12.4.50
CiscoAdaptive Security Appliance Software9.12.4.52
CiscoAdaptive Security Appliance Software9.12.4.54
CiscoAdaptive Security Appliance Software9.12.4.55
CiscoAdaptive Security Appliance Software9.12.4.56
CiscoAdaptive Security Appliance Software9.12.4.58
CiscoAdaptive Security Appliance Software9.12.4.62
CiscoAdaptive Security Appliance Software9.12.4.65
CiscoAdaptive Security Appliance Software9.12.4.67
CiscoAdaptive Security Appliance Software9.16.1
CiscoAdaptive Security Appliance Software9.16.1.28
CiscoAdaptive Security Appliance Software9.16.2
CiscoAdaptive Security Appliance Software9.16.2.3
CiscoAdaptive Security Appliance Software9.16.2.7
CiscoAdaptive Security Appliance Software9.16.2.11
CiscoAdaptive Security Appliance Software9.16.2.13
CiscoAdaptive Security Appliance Software9.16.2.14

Showing 50 of 222 affected configurations. See NVD for the full list.

References

Timeline

Published
Last Modified
Status
Analyzed

Frequently Asked Questions

What is 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 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.
How severe is CVE-2026-20100?
CVE-2026-20100 has a CVSS score of 7.7/10 (HIGH severity). The EPSS model estimates a 0.28% probability of exploitation in the next 30 days.
How do I fix CVE-2026-20100?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2026-20100?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST