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Vulnerability record · CVE-2026-27749 · published 5 March 2026

CVE-2026-27749: Avira internet security deserialization of untrusted data vulnerability

Avira · Internet Security

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.

7.8 CVSS 3.1 High EPSS 0.69% · top 49.3% CWE-502 · Deserialization of untrusted data
7.8CVSS 3.1 base score
0.69%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
3References
17 Jun 2026Last modified by NVD

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.

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://support.avira.com/hc/en-us/articles/360010656158-Current-Avira-versions Release Notes
https://www.avira.com/en/internet-security Product
https://www.gendigital.com/us/en/contact-us/security-advisories/

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Source: NIST National Vulnerability Database (record CVE-2026-27749), CISA KEV, FIRST EPSS (scores of 2026-09-26). This page is refreshed as NVD updates the record.