What’s Vulnerable › Vulnerabilities

CVE-2026-27750: Avira Internet Security Optimizer TOCTOU

• Severity: high (CVSS 7.0 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.1% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-03-05 · updated 2026-06-17
• Weakness: CWE-367

Description

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.

Affected products

• Gen Digital Inc. Avira Internet Security: before 1.1.114.3113 — fixed in 1.1.114.3113

How to fix

Upgrade to a fixed version: Gen Digital Inc. Avira Internet Security 1.1.114.3113. Check the vendor advisory for mitigations.

References

• https://support.avira.com/hc/en-us/articles/360010656158-Current-Avira-versions
• https://www.avira.com/en/internet-security
• https://www.gendigital.com/us/en/contact-us/security-advisories/

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