CVE-2026-27749 json
Avira Internet Security System Speedup Insecure Deserialization
published 2026-03-05 8 mo ago modified 2026-06-17 4 mo ago also EUVD-2026-9821
- cvss
- 7.8
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.4%
- EPSS 0.4% chance of exploitation in 30 days, percentile 29%
- public exploits
- 0
- none known
Summary
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.
Patch / fix
- Gen Digital Inc. Avira Internet Security 1.1.114.3113
CISA SSVC
- Exploitation
- Proof of concept is public
- Automatable
- no
- Technical impact
- total
- Assessed
- 8 mo ago
Exploit prediction
0.36% chance of exploitation in the next 30 days, higher than 29% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 7.8 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
Affected products
- Gen Digital Inc. Avira Internet Security
Classification
- Weakness
-
- CWE-502 Deserialization of Untrusted Data
References
-
gendigital.com
/us/en/contact-us/security-advisories/
vendor-advisory
-
support.avira.com
/hc/en-us/articles/360010656158-Current-Avira-versions
release-notes
-
avira.com
/en/internet-security
product
Sources
- CVE List CVE-2026-27749
- NVD CVE-2026-27749
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