CVE-2026-27749: Avira Internet Security

High severity, CVSS 7.8. EPSS: 0.8% chance of exploitation in the next 30 days.

Avira Internet Security contains a deserialization of untrusted data vulnerability in the System Speedup component. The Avira.SystemSpeedup.RealTimeOptimizer.exe process, which runs with SYSTEM privileges, deserializes data from a file located in C:\\ProgramData using .NET BinaryFormatter without implementing input validation or deserialization safeguards. Because the file can be created or modified by a local user in default configurations, an attacker can supply a crafted serialized payload that is deserialized by the privileged process, resulting in arbitrary code execution as SYSTEM.

Affected products

• Avira Internet Security: before 1.1.114.3113 (fixed in 1.1.114.3113)

Published 2026-03-05. Last modified 2026-06-17.