CVE-2026-20243

ClamAV ALZ Archive Processing Denial of Service Vulnerability

Severity
High 7.5
CVSS 3.1
Exploited
Not listed
EPSS
0.005
40.1th percentile
Discovered by
Third party
Published by the vendor
Published
Jul 1, 2026
Assigned by cisco

Description

A vulnerability in the ALZ file format parser of ClamAV could allow an unauthenticated, remote attacker to cause a DoS condition, or possibly other expanded impacts, resulting from memory corruption on an affected device. This vulnerability is due to improper boundary checks for content in ALZ files during scanning, which may result in an out-of-bounds buffer write. An attacker could exploit this vulnerability by submitting a crafted file that contains ALZ content to be scanned by ClamAV on an affected device. A successful exploit could allow the attacker to cause the ClamAV scanning process to terminate, resulting in a DoS condition on the affected software.

Weakness: CWE-120

Affected products

Vendor Product Category Matched by
Cisco Cisco Secure Endpoint Endpoint / EDR cna-assigner
Vendor-reported affected versions (1)
  • Cisco · Cisco Secure Endpoint