Vulnerability in Cisco Secure Firewall Threat Defense
CVSS score
8.6
EPSS probability
%0.4
Risk score
0.0
Published
7 mo ago
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Impact on My Inventory
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Vulnerability description
DayBreach CVE AI Research
CVE-2026-20039 has vendor, distribution, patch and security-source records on file. We can compare them and prepare an explanation linked to the evidence.
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.
IMPACT: Affected Products and Software
Affected Products
The following products are affected by CVE-2026-20039 vulnerability. Where our threat engine knows the exact affected versions, they are listed below.
| ID | VENDOR | PRODUCT | ACTION |
|---|---|---|---|
| 1 | cisco | adaptive security appliance software | View |
| 2 | cisco | adaptive security appliance software | View |
| 3 | cisco | adaptive security appliance software | View |
| 4 | cisco | adaptive security appliance software | View |
| 5 | cisco | adaptive security appliance software | View |
| 6 | cisco | secure firewall threat defense | View |
| 7 | cisco | secure firewall threat defense | View |
| 8 | cisco | secure firewall threat defense | View |
| 9 | cisco | secure firewall threat defense | View |
| 10 | cisco | secure firewall threat defense | View |
RED HAT CSAF/VEX: Product Impact Check
SCORING: CVSS from Multiple Sources
CVSS Scores
The Common Vulnerability Scoring System is a standardised framework for assessing the severity of vulnerabilities in software and systems. We collect and display CVSS scores from several sources for each CVE.
| SCORE | VERSION | SEVERITY | VECTOR | SOURCE |
|---|---|---|---|---|
| 8.6 | CVSS V31 | HIGH | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H | NVD |
Patch and Remediation Guide
Solution & Remediation Advisory
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Public exploit and active exploitation status
Verified exploit intelligence
No verified public PoC, exploit repository or Metasploit module has been found for this CVE yet.
Weakness Classification and Attack Patterns (CWE & CAPEC)
CWE - Common Weakness Enumeration
While CVE identifies specific instances of vulnerabilities, CWE categorises the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-20039 is associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-20039 weaknesses.
Attack Vector and Accessibility
Official Sources and Advisories
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Get this vulnerability through the API
Affected products, version ranges, exploitation status and patch information in a single request, with a free key.
curl -H "x-api-key: $DAYBREACH_API_KEY" \ "https://api.enginteksut.com.tr/api/v1/intel/cves/CVE-2026-20039"