CVE-2026-27750 HIGH

CVE-2026-27750: Avira Internet Security Optimizer TOCTOU

Vendor Gen Digital Inc.
Product Avira Internet Security
Weakness CWE-367
Published March 5, 2026
Last update April 1, 2026

CVSS base score

7.8/10
Attack vector Local
Attack complexity Low
Privileges required Low
User interaction None
Confidentiality High
Integrity High

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

What the vulnerability does

01Description

Avira Internet Security contains a time-of-check time-of-use (TOCTOU) vulnerability in the Optimizer component. A privileged service running as SYSTEM identifies directories for cleanup during a scan phase and subsequently deletes them during a separate cleanup phase without revalidating the target path. A local attacker can replace a previously scanned directory with a junction or reparse point before deletion occurs, causing the privileged process to delete an unintended system location. This may result in deletion of protected files or directories and can lead to local privilege escalation, denial of service, or system integrity compromise depending on the affected target.

Key dates

02Disclosure timeline

March 5, 2026 CVE published
April 1, 2026 Record updated