CVE-2021-45339: Avast Antivirus

High severity, CVSS 7.8. EPSS: 0.3% chance of exploitation in the next 30 days.

Privilege escalation vulnerability in Avast Antivirus prior to 20.4 allows a local user to gain elevated privileges by "hollowing" trusted process which could lead to the bypassing of Avast self-defense.

Affected products

• Avast Antivirus: before 20.4 (fixed in 20.4)

Published 2021-12-27. Last modified 2026-06-17.