CVE-2026-27749
Deserialization Vulnerability in Avira System Speedup Enables SYSTEM Code Execution
Publication date: 2026-03-05
Last updated on: 2026-04-01
Assigner: VulnCheck
Description
Description
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| avira | internet_security | to 1.1.114.3113 (exc) |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-502 | The product deserializes untrusted data without sufficiently ensuring that the resulting data will be valid. |
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?
[{'type': 'paragraph', 'content': "CVE-2026-27749 is a high-severity vulnerability in Avira Internet Security's System Speedup component. The issue arises because the Avira.SystemSpeedup.RealTimeOptimizer.exe process, which runs with SYSTEM privileges, deserializes data from a file in C:\\ProgramData using the .NET BinaryFormatter without validating the input or using deserialization safeguards."}, {'type': 'paragraph', 'content': 'Since the file can be created or modified by a local user under default settings, an attacker can supply a specially crafted serialized payload. When this payload is deserialized by the privileged process, it can lead to arbitrary code execution with SYSTEM-level privileges.'}] [1]
How can this vulnerability impact me? :
This vulnerability allows a local attacker to escalate their privileges to SYSTEM level by exploiting insecure deserialization in a highly privileged process. This means an attacker with limited access could execute arbitrary code with the highest system privileges, potentially taking full control of the affected system.
How does this vulnerability affect compliance with common standards and regulations (like GDPR, HIPAA)?:
I don't know
How can this vulnerability be detected on my network or system? Can you suggest some commands?
[{'type': 'paragraph', 'content': 'Detection of this vulnerability involves checking for the presence and version of the Avira Internet Security System Speedup component, specifically the Avira.SystemSpeedup.RealTimeOptimizer.exe process running with SYSTEM privileges.'}, {'type': 'paragraph', 'content': 'You can verify if the vulnerable executable is running by using system process listing commands.'}, {'type': 'list_item', 'content': 'On Windows, use: tasklist /FI "IMAGENAME eq Avira.SystemSpeedup.RealTimeOptimizer.exe"'}, {'type': 'list_item', 'content': 'Check the file in C:\\ProgramData that the process deserializes from, to see if it has been modified or created by an untrusted user.'}, {'type': 'paragraph', 'content': 'Since the vulnerability involves deserialization of untrusted data from a file, monitoring file changes in C:\\ProgramData related to Avira System Speedup may help detect exploitation attempts.'}] [1]
What immediate steps should I take to mitigate this vulnerability?
Immediate mitigation steps include restricting write permissions to the file in C:\ProgramData that is deserialized by Avira.SystemSpeedup.RealTimeOptimizer.exe to prevent untrusted users from modifying or creating the file.
Additionally, ensure that the Avira Internet Security System Speedup component is updated to a version that addresses this vulnerability, if available.
As a temporary measure, consider stopping or disabling the Avira.SystemSpeedup.RealTimeOptimizer.exe process if it is not critical to your system operations.