CVE-2026-13268: G DATA Total Security Privilege Escalation

CVE-2026-13268 Overview

CVE-2026-13268 is a local privilege escalation vulnerability in the G DATA Total Security Backup Service. The flaw stems from improper handling of symbolic links [CWE-59], allowing a low-privileged local attacker to abuse the service to delete arbitrary files. Successful exploitation leads to code execution in the context of SYSTEM on affected Windows installations. The issue was disclosed through the Zero Day Initiative as ZDI-CAN-28665 and tracked as ZDI-26-432.

Critical Impact
An authenticated local attacker can escalate from a standard user account to SYSTEM, gaining full control over the affected host.

Affected Products

G DATA Total Security (Backup Service component)

Discovery Timeline

2026-07-29 - CVE-2026-13268 published to NVD
2026-07-30 - Last updated in NVD database

Technical Details for CVE-2026-13268

Vulnerability Analysis

The vulnerability resides in the Backup Service shipped with G DATA Total Security. The service performs file operations from a privileged context without properly validating whether target paths traverse symbolic links or junctions. An attacker with the ability to run low-privileged code on the host can plant a symbolic link that redirects a service-initiated file deletion to an attacker-chosen location. Because the Backup Service runs with SYSTEM privileges, the delete operation is performed against paths the unprivileged user would otherwise be unable to modify.

Arbitrary file deletion as SYSTEM is a well-established primitive for full local privilege escalation on modern Windows. Attackers commonly transform such primitives into code execution by manipulating Windows Installer rollback directories or similar system-controlled paths, then loading attacker-supplied binaries into a privileged process.

Root Cause

The root cause is a link-following flaw [CWE-59]. The Backup Service resolves file paths without verifying that intermediate directories and target files are not symbolic links or NTFS junctions controlled by an unprivileged user. This missing check enables a classic time-of-use path substitution against a privileged file operation.

Attack Vector

Exploitation requires local access and the ability to execute code as an unprivileged user. The attacker creates a symbolic link or junction from a user-writable directory to a protected file on the system, then triggers the Backup Service operation that deletes the linked path. The service follows the link and removes the target file with SYSTEM privileges, which the attacker then leverages to plant privileged content and execute arbitrary code.

No public exploit is currently listed for CVE-2026-13268. Technical details are available in the Zero Day Initiative Advisory ZDI-26-432.

Detection Methods for CVE-2026-13268

Indicators of Compromise

Creation of symbolic links or NTFS junctions in user-writable directories that point to files under C:\Windows, C:\Program Files, or other SYSTEM-owned paths.
Unexpected deletion of files owned by SYSTEM shortly after G DATA Backup Service activity.
Backup Service process performing file I/O on paths outside of configured backup targets.

Detection Strategies

Monitor for CreateSymbolicLink, mklink, and reparse-point creation events initiated by non-administrative users.
Correlate file-delete events by the G DATA Backup Service process with the presence of reparse points on the deletion path.
Alert on privilege escalation patterns where an unprivileged process is followed by a new SYSTEM-level child process on the same host.

Monitoring Recommendations

Enable Windows object access auditing on directories writable by standard users to capture reparse-point creation.
Ingest Sysmon Event ID 11 (FileCreate) and Event ID 23 (FileDelete) into a centralized log store for correlation.
Track behavioral indicators such as unprivileged-to-SYSTEM transitions and unusual file activity by security product services.

How to Mitigate CVE-2026-13268

Immediate Actions Required

Apply the vendor update for G DATA Total Security as soon as it is available from G DATA.
Restrict interactive and remote access on endpoints running G DATA Total Security to trusted users only.
Audit standard-user accounts for the ability to create symbolic links; remove the SeCreateSymbolicLinkPrivilege where it is not required.

Patch Information

Refer to the Zero Day Initiative Advisory ZDI-26-432 for the current vendor coordination status and any released patches from G DATA.

Workarounds

Disable the G DATA Backup Service on hosts where backup functionality is not required until a patch is applied.
Remove SeCreateSymbolicLinkPrivilege from standard users via Group Policy to limit the ability to plant reparse points.
Limit local logon rights on affected endpoints to reduce the population of accounts able to stage the attack.

bash

# Remove symbolic link creation privilege from non-admin users via secedit
# Export current policy
secedit /export /cfg C:\policy.cfg

# Edit C:\policy.cfg and set:
# SeCreateSymbolicLinkPrivilege = *S-1-5-32-544

# Apply the updated policy
secedit /configure /db C:\Windows\security\local.sdb /cfg C:\policy.cfg /areas USER_RIGHTS