Is CVE-2026-20100 being actively exploited?

CVE-2026-20100 is not currently listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.

What is the CVSS score for CVE-2026-20100?

CVE-2026-20100 has a CVSS 3.1 base score of 7.7 (HIGH).

CVE-2026-20100

HIGH · CVSS 7.7EPSS 0.3%EU EUVD

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.

Key facts

CVSS score: 7.7 (v3.1)
Severity: HIGH
CVSS vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H
Weakness (CWE): CWE-120
EPSS score: 0.3% (20th percentile)
In CISA KEV: No
In EU EUVD: Yes (EUVD-2026-9439)
Published: March 4, 2026
NVD last modified: August 11, 2026
Status: Analyzed

EU Vulnerability Database (EUVD)

This vulnerability is also tracked by ENISA as EUVD-2026-9439 in the EU Vulnerability Database. Last updated in EUVD on March 5, 2026.

View on the EU Vulnerability Database

Affected products

cisco / adaptive security appliance software
cisco / adaptive security appliance software
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cisco / adaptive security appliance software
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cisco / adaptive security appliance software
cisco / adaptive security appliance software
cisco / adaptive security appliance software

and 172 more…

Certified products that may be affected

2 FIPS 140 or Common Criteria certified products, from automated matching by sec-certs.org.

Cisco Secure Firewall Threat Defense (FTD) 7.4 with Secure Firewall Management Center (FMC) 7.4 and Secure Client 5.1 - Cisco Systems, Inc. - Common Criteria NSCIB-CC-2400046-01-CR - active
Cisco Secure Firewall Threat Defense Virtual 7.4 with FMC/FMCv - Cisco Systems, Inc. - Common Criteria CCEVS-VR-VID-11510-2025 - active

References

https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asaftd-vpn-m9sx6MbC(Vendor Advisory)

Last updated September 17, 2026 · Source: NVD, CISA KEV, FIRST.org EPSS

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