Medium severity · published Mar 4, 2026
CVE-2026-20052
Cisco Secure Firewall Threat Defense Software Snort 3 Memory Management Denial of Service Vulnerability
5.8
CVSS
0.4%
EPSS
No
On KEV
Description
A vulnerability in the memory management handling for 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 restart.
This vulnerability is due to a logic error in memory management when a device is performing Snort 3 SSL packet inspection. An attacker could exploit this vulnerability by sending crafted SSL packets through an established connection to be parsed by the Snort 3 Detection Engine. A successful exploit could allow the attacker to cause a denial of service (DoS) condition when the Snort 3 Detection Engine unexpectedly restarts.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:L
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
None
Integrity
None
Availability
Low
Scope
Changed
Exploitation
Is it being used?
Exploit prediction (EPSS)0.4% · higher than 38% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
CS
Cisco Secure Firewall Threat Defense (FTD) Software · Cisco
7.4.0; 7.4.1; 7.4.1.1; 7.6.0; 7.4.2; 7.4.2.1 · source: vendor
SF
Secure Firewall Threat Defense · Cisco
7.4.0; 7.4.1; 7.4.1.1; 7.4.2; 7.4.2.1; 7.6.0 · source: NVD
Affected product
CS
Cisco Secure Firewall Threat Defense (FTD) Software
Cisco
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-20052
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-20052
Vendor Advisory
https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ftd-snort3ssl-FBEKYXpH
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