7.8

CVE-2026-27749: avira internet_security Deserialization of Untrusted Data

CVSS: 7.8v3.1HighModified
Published 05-03-2026Last modified 01-04-2026
Open JSON

Vulnerability summary

CVE-2026-27749 is a high (CVSS 7.8) Deserialization of Untrusted Data vulnerability in avira internet_security. EPSS estimates a 0.77% chance of exploitation in the next 30 days, higher than 54.7% of scored vulnerabilities.

Overall risk
31/100
0100
Medium · default modelHow is this calculated?
CVSS score
7.8/10
010
High · v3.1 (CVE.org)
EPSS score
0.77%
0%100%
Low · +0.44 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Timeline

  1. 05-03-2026
    PublishedVulnerability first disclosed.
  2. 01-04-2026
    Last modifiedVulnerability information updated.

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 metrics

2 scores · 2 sources · 1 version

EPSS trend

Probability

0.77%

Chance of exploitation in the next 30 days

Percentile

55%

Versus all other CVEs

30-day change

+0.44 pp

From 0.32% on 20-09-2026

20-09-202620-10-2026
EPSS score
0.77%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Avira1 product
Gen digital inc.1 product

2 vendors · 2 products

References

3 links