CVE-2026-27749Public exploit

Local SYSTEM code execution via BinaryFormatter deserialization

Published Mar 5, 2026 · Updated Mar 5, 2026

Deserialization of untrusted data in Gen Digital Avira Internet Security through 1.1.109.1990 allows local users to execute code as SYSTEM. Avira.SystemSpeedup.RealTimeOptimizer.exe passes the user-writable temp_rto.dat stream to BinaryFormatter.Deserialize without validation or a type filter. Enabling Performance Booster starts the SYSTEM process; the crafted payload then executes without user interaction or a race.

CVSS severity8.5
High
EPSS probability0.32%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Deserialization of untrusted data in Gen Digital Avira Internet Security through 1.1.109.1990 allows local users to execute code as SYSTEM. Avira.SystemSpeedup.RealTimeOptimizer.exe passes the user-writable temp_rto.dat stream to BinaryFormatter.Deserialize without validation or a type filter. Enabling Performance Booster starts the SYSTEM process; the crafted payload then executes without user interaction or a race.

The record

CVE
CVE-2026-27749
Published
Mar 5, 2026
Updated
Mar 5, 2026
Vendor
Gen Digital
Product
Avira Internet Security
Classifications
CWE-502, T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Mar 5, 2026CVE publishedPublication date reported by the CVE source.
  2. Mar 5, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <=1.1.109.1990

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Gen Digital · Avira Internet Securityversion=0 <=1.1.109.1990

Published CVSS scores

7.8Gen Digital Inc.CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
8.5Gen Digital Inc.CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-502Deserialization of Untrusted Data
T1068Exploitation for Privilege Escalation

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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