Cisco Secure Firewall Threat Defense Software Snort 2 SSL/TLS Denial of Service Vulnerability

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2026-20290
StatePUBLISHED
Assignercisco
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-09-16 21:17:09 UTC
Updated2026-09-16 21:17:09 UTC
DescriptionA vulnerability in SSL/TLS certificate parsing in the Snort 2 Detection Engine of Cisco Secure Firewall Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause the Snort 2 Detection Engine to restart. This vulnerability is due to incomplete validation of the SSL certificate. An attacker could exploit this vulnerability by sending a crafted SSL connection setup request to be parsed by Snort 2. A successful exploit could allow the attacker to cause the Snort 2 Detection Engine to restart unexpectedly, resulting in a denial of service (DoS) condition.

Risk And Classification

Primary CVSS: v3.1 5.8 MEDIUM from [email protected]

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:L

Problem Types: CWE-805 | CWE-805 Buffer Access with Incorrect Length Value

VersionSourceTypeScoreSeverityVector
3.1[email protected]Primary5.8MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:L
3.1CNACVSSV3_15.8MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:L

CVSS v3.1 Breakdown

Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Changed
Confidentiality
None
Integrity
None
Availability
Low

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:L

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Cisco Cisco Secure Firewall Threat Defense FTD Software affected 7.0.0 Not specified
CNA Cisco Cisco Secure Firewall Threat Defense FTD Software affected 7.0.0.1 Not specified
CNA Cisco Cisco Secure Firewall Threat Defense FTD Software affected 7.0.1 Not specified
CNA Cisco Cisco Secure Firewall Threat Defense FTD Software affected 7.0.1.1 Not specified
CNA Cisco Cisco Secure Firewall Threat Defense FTD Software affected 7.0.2 Not specified
CNA Cisco Cisco Secure Firewall Threat Defense FTD Software affected 7.2.0 Not specified
CNA Cisco Cisco Secure Firewall Threat Defense FTD Software affected 7.0.2.1 Not specified
CNA Cisco Cisco Secure Firewall Threat Defense FTD Software affected 7.0.3 Not specified
CNA Cisco Cisco Secure Firewall Threat Defense FTD Software affected 7.2.0.1 Not specified
CNA Cisco Cisco Secure Firewall Threat Defense FTD Software affected 7.0.4 Not specified
CNA Cisco Cisco Secure Firewall Threat Defense FTD Software affected 7.2.1 Not specified
CNA Cisco Cisco Secure Firewall Threat Defense FTD Software affected 7.0.5 Not specified
CNA Cisco Cisco Secure Firewall Threat Defense FTD Software affected 7.3.0 Not specified
CNA Cisco Cisco Secure Firewall Threat Defense FTD Software affected 7.2.2 Not specified
CNA Cisco Cisco Secure Firewall Threat Defense FTD Software affected 7.2.3 Not specified
CNA Cisco Cisco Secure Firewall Threat Defense FTD Software affected 7.3.1 Not specified
CNA Cisco Cisco Secure Firewall Threat Defense FTD Software affected 7.2.4 Not specified
CNA Cisco Cisco Secure Firewall Threat Defense FTD Software affected 7.0.6 Not specified
CNA Cisco Cisco Secure Firewall Threat Defense FTD Software affected 7.2.5 Not specified
CNA Cisco Cisco Secure Firewall Threat Defense FTD Software affected 7.2.4.1 Not specified
CNA Cisco Cisco Secure Firewall Threat Defense FTD Software affected 7.3.1.1 Not specified
CNA Cisco Cisco Secure Firewall Threat Defense FTD Software affected 7.4.0 Not specified
CNA Cisco Cisco Secure Firewall Threat Defense FTD Software affected 7.0.6.1 Not specified
CNA Cisco Cisco Secure Firewall Threat Defense FTD Software affected 7.2.5.1 Not specified
CNA Cisco Cisco Secure Firewall Threat Defense FTD Software affected 7.4.1 Not specified
CNA Cisco Cisco Secure Firewall Threat Defense FTD Software affected 7.2.6 Not specified
CNA Cisco Cisco Secure Firewall Threat Defense FTD Software affected 7.0.6.2 Not specified
CNA Cisco Cisco Secure Firewall Threat Defense FTD Software affected 7.4.1.1 Not specified
CNA Cisco Cisco Secure Firewall Threat Defense FTD Software affected 7.2.7 Not specified
CNA Cisco Cisco Secure Firewall Threat Defense FTD Software affected 7.2.5.2 Not specified
CNA Cisco Cisco Secure Firewall Threat Defense FTD Software affected 7.3.1.2 Not specified
CNA Cisco Cisco Secure Firewall Threat Defense FTD Software affected 7.2.8 Not specified
CNA Cisco Cisco Secure Firewall Threat Defense FTD Software affected 7.6.0 Not specified
CNA Cisco Cisco Secure Firewall Threat Defense FTD Software affected 7.4.2 Not specified
CNA Cisco Cisco Secure Firewall Threat Defense FTD Software affected 7.2.8.1 Not specified
CNA Cisco Cisco Secure Firewall Threat Defense FTD Software affected 7.0.6.3 Not specified
CNA Cisco Cisco Secure Firewall Threat Defense FTD Software affected 7.4.2.1 Not specified
CNA Cisco Cisco Secure Firewall Threat Defense FTD Software affected 7.2.9 Not specified
CNA Cisco Cisco Secure Firewall Threat Defense FTD Software affected 7.0.7 Not specified
CNA Cisco Cisco Secure Firewall Threat Defense FTD Software affected 7.4.2.2 Not specified
CNA Cisco Cisco Secure Firewall Threat Defense FTD Software affected 7.2.10 Not specified
CNA Cisco Cisco Secure Firewall Threat Defense FTD Software affected 7.6.1 Not specified
CNA Cisco Cisco Secure Firewall Threat Defense FTD Software affected 7.4.2.3 Not specified
CNA Cisco Cisco Secure Firewall Threat Defense FTD Software affected 7.0.8 Not specified
CNA Cisco Cisco Secure Firewall Threat Defense FTD Software affected 7.6.2 Not specified
CNA Cisco Cisco Secure Firewall Threat Defense FTD Software affected 7.0.8.1 Not specified
CNA Cisco Cisco Secure Firewall Threat Defense FTD Software affected 7.6.2.1 Not specified
CNA Cisco Cisco Secure Firewall Threat Defense FTD Software affected 7.4.2.4 Not specified
CNA Cisco Cisco Secure Firewall Threat Defense FTD Software affected 7.2.10.2 Not specified
CNA Cisco Cisco Secure Firewall Threat Defense FTD Software affected 7.4.3 Not specified
CNA Cisco Cisco Secure Firewall Threat Defense FTD Software affected 7.6.4 Not specified
CNA Cisco Cisco Secure Firewall Threat Defense FTD Software affected 7.4.4 Not specified
CNA Cisco Cisco Secure Firewall Threat Defense FTD Software affected 7.0.9 Not specified
CNA Cisco Cisco Secure Firewall Threat Defense FTD Software affected 7.2.11 Not specified
CNA Cisco Cisco Secure Firewall Threat Defense FTD Software affected 7.4.7 Not specified

References

ReferenceSourceLinkTags
sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ftd-sn... [email protected] sec.cloudapps.cisco.com
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

Additional Advisory Data

Exploits

CNA: 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.

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