CVE-2026-20006: cisco cisco secure firewall threat defense (ftd) software 7PK - Errors
Vulnerability summary
CVE-2026-20006 is a medium (CVSS 5.8) 7PK - Errors vulnerability in cisco cisco secure firewall threat defense (ftd) software. EPSS estimates a 0.40% chance of exploitation in the next 30 days, higher than 32.6% of scored vulnerabilities.
Timeline
- 04-03-2026PublishedVulnerability first disclosed.
- 04-03-2026Last modifiedVulnerability information updated.
Description
A vulnerability in the TLS cryptography functionality of the Snort 3 Detection Engine of Cisco Secure Firewall Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause the Snort 3 Detection Engine to unexpectedly restart, resulting in a denial of service (DoS) condition. This vulnerability is due to improper implementation of the TLS protocol. An attacker could exploit this vulnerability by sending a crafted TLS packet to an affected system. A successful exploit could allow the attacker to cause a device that is running Cisco Secure FTD Software to drop network traffic, resulting in a DoS condition. Note: TLS 1.3 is not affected by this vulnerability.
CVSS metrics
2 scores · 2 sources · 1 version- NVDNIST5.8MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:L
EPSS trend
Probability
0.40%
Chance of exploitation in the next 30 days
Percentile
33%
Versus all other CVEs
30-day change
+0.02 pp
From 0.37% on 21-09-2026
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Cisco2 products
- cisco secure firewall threat defense (ftd) software7.2.0 | 7.2.0.1 | 7.2.1 | 7.3.0 | 7.2.2 | 7.2.3 | 7.3.1 | 7.2.4 | 7.2.5 | 7.2.4.1 | 7.3.1.1 | 7.4.0 | 7.2.5.1 | 7.4.1 | 7.2.6 | 7.4.1.1 | 7.2.7 | 7.2.5.2 | 7.3.1.2 | 7.2.8 | 7.6.0 | 7.4.2 | 7.2.8.1 | 7.4.2.1 | 7.2.9 | 7.4.2.2 | 7.2.10 | 7.6.1 | 7.4.2.3 | 7.6.2 | 7.6.2.1 | 7.4.2.4 | 7.2.10.2
- secure_firewall_threat_defense7.2.0 | 7.2.0.1 | 7.2.1 | 7.2.2 | 7.2.3 | 7.2.4 | 7.2.4.1 | 7.2.5 | 7.2.5.1 | 7.2.5.2 | 7.2.6 | 7.2.7 | 7.2.8 | 7.2.8.1 | 7.2.9 | 7.2.10 | 7.2.10.2 | 7.3.0 | 7.3.1 | 7.3.1.1 | 7.3.1.2 | 7.4.0 | 7.4.1 | 7.4.1.1 | 7.4.2 | 7.4.2.1 | 7.4.2.2 | 7.4.2.3 | 7.4.2.4 | 7.6.0 | 7.6.1 | 7.6.2 | 7.6.2.1
1 vendor · 2 products
References
1 links- sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ftd-tcp-dos-rHfqnwRgVendor AdvisoryMitigation