CVE-2026-27749

High

Description

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.

SeverityHigh

CVSS7.8

Exploit probability—

ProductAvira Internet Security

PublishedMar 5, 2026

First seenMar 5, 2026

Weakness typeCWE-502Deserialization of untrusted data

How to fix

Update

avira internet_security1.1.114.3113 or later

Vendor advisories

Affected products

Product	Affected versions	Fixed in
avira internet_security	v < 1.1.114.3113	1.1.114.3113

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