CVE-2026-20214

ClamAV FSG File Format Processing Out-of-Bounds Memory Corruption Vulnerability

Published Jul 1, 2026 CVSS 3.1 · 7.5 High EPSS < 1% KEV · Not listed
Description
A vulnerability in the FSG 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 FSG 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 portable executable content compressed with FSG 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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Debian DLA Debian DLA DLA-4852-1 clamav security update
Ubuntu USN Ubuntu USN USN-8517-1 ClamAV vulnerabilities
History
Type Values Removed Values Added
First Time appeared Cisco
Cisco secure Endpoint
Vendors & Products Cisco
Cisco secure Endpoint
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description A vulnerability in the FSG 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 FSG 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 portable executable content compressed with FSG 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.
Title ClamAV FSG File Format Processing Out-of-Bounds Memory Corruption Vulnerability
Weaknesses CWE-120
References
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
cisco
Published
Updated
Jul 1, 2026, 5:25 PM
Reserved
Oct 8, 2025, 11:59 AM
Status
Analyzed
Published
Jul 1, 2026, 5:16 PM
Modified
Oct 25, 2026, 5:10 PM
Severity
Important
Public date
Jul 1, 2026, 4:27 PM