CVE-2026-20039A vulnerability in the VPN web server of Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Cisco Secure Firewall Threat Defense (FTD) Software could allow an unauthenticated, remot…
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It affects cisco adaptive_security_appliance_software and 1 other product. Add what you run to find out whether that includes you.
No exploitation reported and no EPSS estimate yet.
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A vulnerability in the VPN web server of Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Cisco Secure Firewall Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability is due to ineffective memory management of the VPN web server. An attacker could exploit this vulnerability by sending a large number of crafted HTTP requests to an affected device. A successful exploit could allow the attacker to cause the device to reload, resulting in a DoS condition.
- CVSS
- 8.6 HIGH (v3.1, NVD)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
- Weakness (CWE)
- CWE-244
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- Not given
- NVD analysis
- Analyzed
- Record last updated
- Aug 11, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
cisco adaptive_security_appliance_software cisco:adaptive_security_appliance_software | from 9.12.1 before 9.16.4.84; from 9.17.1 before 9.18.4.57; from 9.19.1 before 9.20.3.16; from 9.22.1.1 before 9.22.2.4; from 9.23.1 before 9.23.1.3 | NVD |
cisco secure_firewall_threat_defense cisco:secure_firewall_threat_defense | from 6.4.0 before 7.0.9; from 7.1.0 before 7.2.10; from 7.3.0 before 7.4.3; from 7.6.0 before 7.6.1; from 7.7.0 before 7.7.10 | NVD |
References
- https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asaftd-vpn-dos-SpOFF2Revendor-advisory
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.