Integer overflow in ClamAV - CVE-2026-20339
Published: August 7, 2026
Vulnerability identifier: #VU141298
CSH Severity: Medium
CVSS v4: 6.7 [CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-20339
CWE-ID: CWE-190
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to write beyond an undersized buffer.
The vulnerability exists due to integer overflow in the PESpin unpacker when rebuilding a PE file. A remote attacker can provide a crafted PE file to write beyond an undersized buffer.
Affected software
ClamAV
How to mitigate CVE-2026-20339
Install security update from vendor's website.
ClamAV - addressed in versions 1.4.6, 1.5.4