CVE-2026-20052: cisco cisco secure firewall threat defense (ftd) software

Vulnerability summary

CVE-2026-20052 is a medium (CVSS 5.8) vulnerability in cisco cisco secure firewall threat defense (ftd) software. EPSS estimates a 0.44% chance of exploitation in the next 30 days, higher than 37% of scored vulnerabilities.

Timeline

1. 04-03-2026
   PublishedVulnerability first disclosed.
2. 04-03-2026
   Last modifiedVulnerability information updated.

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.

• CWE-788Access of Memory Location After End of BufferThe product reads or writes to a buffer using an index or pointer that references a memory location after the end of the buffer.