CVE-2026-27749 PUBLISHED

Avira Internet Security System Speedup Insecure Deserialization

Assigner: VulnCheck
Reserved: 23.02.2026 Published: 05.03.2026 Updated: 05.03.2026

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.

Metrics

CVSS Vector: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
CVSS Score: 8.5

Product Status

Vendor Gen Digital Inc.
Product Avira Internet Security
Versions Default: unaffected
  • affected from 0 to 1.1.109.1990 (incl.)
  • Version 1.1.114.3113 is unaffected

Credits

  • Quarkslab finder

References

Problem Types

  • CWE-502 Deserialization of Untrusted Data CWE