Deserialization in Avira Internet Security
CVE-2026-27749
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.
Vulnerability class: Insecure Deserialization
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.8 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.007 (50.8th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 51st percentile — 50.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.003 · newest: 0.007 · change: +0.004
Affected products
- Avira Internet Security
- Gen Digital Inc. Avira Internet Security — versions 0, 1.1.114.3113
Weakness classification (CWE)
References
- support.avira.com/hc/en-us/articles/360010656158-Current-Avira-versions (release-notes, Release Notes)
- www.avira.com/en/internet-security (Product, product)
- www.gendigital.com/us/en/contact-us/security-advisories/ (vendor-advisory)
Frequently asked questions
- What is CVE-2026-27749?
- CVE-2026-27749 is a high-severity vulnerability in Avira Internet Security, classified under Deserialization of Untrusted Data. CVSS score: 7.8/10. Published 2026-03-05.
- How severe is CVE-2026-27749?
- High severity. CVSS v3 base score is 7.8 out of 10.