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Vulnerabilities

Vulnerability · CVE-2026-20006

A vulnerability in the TLS cryptography functionality of the Snort 3 Detection Engine of Cisco Secure Firewall Threat Defense (FTD) Software could allow an unauthentic…

Published Mar 4, 2026 · catalog updated Aug 20, 2026 · secure firewall threat defense

Check if you run it

No confirmed exploitation is on record for CVE-2026-20006. EPSS is 0.39%. Act only if a listed version of secure firewall threat defense is installed.

Gaps on this record

  • No vendor fix or required action is stored. Compare the linked advisory before you change production.
Severity
Medium5.8
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
0.39%
Remediation
Advisory link
Affected products
cpe cisco/secure firewall threat defense

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.

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • cpe cisco/secure firewall threat defense7.2.0
  • cpe cisco/secure firewall threat defense7.2.0.1
  • cpe cisco/secure firewall threat defense7.2.1
  • cpe cisco/secure firewall threat defense7.2.2
  • cpe cisco/secure firewall threat defense7.2.3
  • cpe cisco/secure firewall threat defense7.2.4
  • cpe cisco/secure firewall threat defense7.2.4.1
  • cpe cisco/secure firewall threat defense7.2.5

How to fix CVE-2026-20006

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

No confirmed exploitation is on record for CVE-2026-20006. EPSS is 0.39%. Act only if a listed version of secure firewall threat defense is installed.

Which versions are affected?

Compare what you have installed with cisco/secure firewall threat defense 7.2.0; cisco/secure firewall threat defense 7.2.0.1; cisco/secure firewall threat defense 7.2.1; cisco/secure firewall threat defense 7.2.2. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

CWE-388. EPSS 0.39%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Technology hubs

Cisco security

Code

The project this record applies to. Exploit listings stay in References.

No public source repository is identified for this product.

Timeline

Detection, updates, and resolution for this record.

  1. Mar 4, 2026 · NIST NVD

    Detected

    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 exploi

  2. Aug 20, 2026 · NIST NVD

    Updated

    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 exploi

Sources

  • CVE.orgVulnerability recordCVE-2026-20006

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2026-20006

    30-day exploitation probability 0.4%

    first.org
  • NIST NVDVulnerability recordCVE-2026-20006

    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 ser

    nvd.nist.gov

References

Freshness

Last verified in this catalog Oct 18, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.