Cisco Warns of High-Severity ClamAV Vulnerabilities With Public PoC

Cisco has issued an advisory regarding seven vulnerabilities in the ClamAV engine used by its Secure Endpoint Connector products on Windows, macOS, and Linux. These flaws, identified as CVE-2026-20337 through CVE-2026-20339 and CVE-2026-20345 through CVE-2026-20348, allow for denial-of-service attacks, with public proof-of-concept code already available for two of them. Although not currently exploited in the wild, the issues pose a high risk to Windows environments because the scanning process runs with elevated privileges.

Fixes are available in ClamAV version 1.5.4, and Cisco plans to roll out updated Secure Endpoint Connector software in August. Customers should deploy patches from Cloud releases 4.2.8 and later, as no immediate workarounds exist.