CVE-2026-27749
HIGHCVSS Vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Lifecycle Timeline
2Tags
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.
Analysis
Arbitrary code execution as SYSTEM in Avira Internet Security's System Speedup component occurs when the privileged RealTimeOptimizer.exe process deserializes untrusted .NET binary data from a world-writable ProgramData location without validation. A local attacker can craft a malicious serialized payload to achieve immediate privilege escalation and full system compromise. …
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Remediation
Within 24 hours: Identify all systems running Avira Internet Security and document System Speedup component versions. Within 7 days: Implement network segmentation to restrict lateral movement and disable the System Speedup component if business-critical functionality permits. …
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