High severity · published Mar 5, 2026
CVE-2026-27749
Avira Internet Security System Speedup Insecure Deserialization
7.8
CVSS
0.3%
EPSS
No
On KEV
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 vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Attack vector
Local
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.3% · higher than 27% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
AI
Avira Internet Security · Gen Digital Inc.
through 1.1.109.1990 · source: vendor
IS
Internet Security · Avira
before 1.1.114.3113 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-27749
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-27749
Release Notes
https://support.avira.com/hc/en-us/articles/360010656158-Current-Avira-versions
Product
https://www.avira.com/en/internet-security
www.gendigital.com
https://www.gendigital.com/us/en/contact-us/security-advisories/
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