Vulnerability in Avira Internet Security
CVE-2026-27750
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.
Vulnerability class: TOCTOU (Time-of-Check to Time-of-Use)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.8 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.001 (2.4th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 2nd percentile — 2.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.001 · newest: 0.001 · change: +0.000
Affected products
- Avira Internet Security
- Gen Digital Inc. Avira Internet Security — versions 0, 1.1.114.3113
Weakness classification (CWE)
References
- support.avira.com/hc/en-us/articles/360010656158-Current-Avira-versions (release-notes, Release Notes)
- www.avira.com/en/internet-security (Product, product)
- www.gendigital.com/us/en/contact-us/security-advisories/ (vendor-advisory)
Frequently asked questions
- What is CVE-2026-27750?
- CVE-2026-27750 is a high-severity vulnerability in Avira Internet Security, classified under Time-of-check Time-of-use (TOCTOU) Race Condition. CVSS score: 7.8/10. Published 2026-03-05.
- How severe is CVE-2026-27750?
- High severity. CVSS v3 base score is 7.8 out of 10.