CVE-2026-27748
Severity CVSS v4.0:
HIGH
Type:
CWE-59
Link Following
Publication date:
05/03/2026
Last modified:
05/03/2026
Description
Avira Internet Security contains an improper link resolution vulnerability in the Software Updater component. During the update process, a privileged service running as SYSTEM deletes a file under C:\\ProgramData without validating whether the path resolves through a symbolic link or reparse point. A local attacker can create a malicious link to redirect the delete operation to an arbitrary file, resulting in deletion of attacker-chosen files with SYSTEM privileges. This may lead to local privilege escalation, denial of service, or system integrity compromise depending on the targeted file and operating system configuration.
Impact
Base Score 4.0
8.50
Severity 4.0
HIGH
Base Score 3.x
7.80
Severity 3.x
HIGH
References to Advisories, Solutions, and Tools
- https://blog.quarkslab.com/avira-deserialize-delete-and-escalate-the-proper-way-to-use-an-av.html
- https://support.avira.com/hc/en-us/articles/360010656158-Current-Avira-versions
- https://www.avira.com/en/internet-security
- https://www.vulncheck.com/advisories/avira-internet-security-arbitrary-file-deletion-via-improper-link-resolution