CVE-2026-20006
Cisco Firepower Threat Defense Software and Cisco FirePOWER Services TLS with Snort 3 Denial of Service Vulnerability
- Published
- Updated
- Reserved
- Assigned by
- cisco
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.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| ciscoCNA (assigner) | 3.1 | Medium5.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:L |
| NVDNVD · Analyzed | 3.1 | Medium5.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:L |
- EPSS (exploitation in 30 days)
- 0.43% · top 62% of all CVEs (4 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: yes · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 5.8.
Weakness
Affected products
Cisco · Cisco Secure Firewall Threat Defense (FTD) Software
- affected 7.2.0
- affected 7.2.0.1
- affected 7.2.1
- affected 7.3.0
- affected 7.2.2
- affected 7.2.3
- affected 7.3.1
- affected 7.2.4
- affected 7.2.5
- affected 7.2.4.1
- affected 7.3.1.1
- affected 7.4.0
- affected 7.2.5.1
- affected 7.4.1
- affected 7.2.6
- affected 7.4.1.1
- affected 7.2.7
- affected 7.2.5.2
- affected 7.3.1.2
- affected 7.2.8
- affected 7.6.0
- affected 7.4.2
- affected 7.2.8.1
- affected 7.4.2.1
- affected 7.2.9
- affected 7.4.2.2
- affected 7.2.10
- affected 7.6.1
- affected 7.4.2.3
- affected 7.6.2
- affected 7.6.2.1
- affected 7.4.2.4
- affected 7.2.10.2
What to do
Exploitation: The Cisco Product Security Incident Response Team (PSIRT) is not aware of any public announcements or malicious use of the vulnerability that is described in this advisory.
References (1)
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2026-20006)Record last updated .