CVE-2026-20027: cisco cisco secure firewall threat defense (ftd) software

Vulnerability summary

CVE-2026-20027 is a medium (CVSS 5.3) vulnerability in cisco cisco secure firewall threat defense (ftd) software. EPSS estimates a 0.60% chance of exploitation in the next 30 days, higher than 47.3% of scored vulnerabilities.

Timeline

1. 07-01-2026
   PublishedVulnerability first disclosed.
2. 12-02-2026
   Last modifiedVulnerability information updated.

Description

Multiple Cisco products are affected by a vulnerability in the processing of DCE/RPC requests that could allow an unauthenticated, remote attacker to cause the Snort 3 Detection Engine to leak sensitive information or to restart, resulting in an interruption of packet inspection. This vulnerability is due to an error in buffer handling logic when processing DCE/RPC requests, which can result in a buffer out-of-bounds read. An attacker could exploit this vulnerability by sending a large number of DCE/RPC requests through an established connection that is inspected by Snort 3. A successful exploit could allow the attacker to obtain sensitive information in the Snort 3 data stream.

• CWE-200Exposure of Sensitive Information to an Unauthorized ActorThe product exposes sensitive information to an actor that is not explicitly authorized to have access to that information.