CVE-2026-41220: Acronis Privilege Escalation Vulnerability

CVE-2026-41220 Overview

CVE-2026-41220 is a local privilege escalation vulnerability affecting Acronis DeviceLock DLP and Acronis Cyber Protect Cloud Agent for Windows. The vulnerability stems from improper input validation, which can be exploited by a local attacker with low privileges to escalate their permissions to higher privilege levels on the affected system. This flaw is classified as CWE-787 (Out-of-bounds Write), indicating that the improper input validation leads to memory corruption that can be leveraged for privilege escalation.

Critical Impact

Local attackers can exploit improper input validation to achieve privilege escalation, potentially gaining full system control on Windows endpoints running vulnerable Acronis security products.

Affected Products

• Acronis DeviceLock DLP (Windows) before build 9.0.93212
• Acronis Cyber Protect Cloud Agent (Windows) before build 42183

Discovery Timeline

• 2026-04-29 - CVE-2026-41220 published to NVD
• 2026-04-29 - Last updated in NVD database

Technical Details for CVE-2026-41220

Vulnerability Analysis

This local privilege escalation vulnerability exists due to improper input validation in Acronis DeviceLock DLP and Cyber Protect Cloud Agent for Windows. The underlying weakness is categorized as CWE-787 (Out-of-bounds Write), which occurs when the software writes data past the end, or before the beginning, of the intended buffer.

In the context of this vulnerability, a local attacker with low-level access to the system can craft malicious input that bypasses validation checks. This allows the attacker to write arbitrary data outside the expected memory boundaries, corrupting adjacent memory structures. By carefully controlling this out-of-bounds write, an attacker can manipulate critical data structures or code pointers to elevate their privileges on the system.

The attack requires local access and low privileges to execute, but requires no user interaction, making it particularly dangerous in environments where multiple users share access to systems or where attackers have gained initial low-privilege footholds.

Root Cause

The root cause of CVE-2026-41220 is improper input validation that fails to adequately verify the size or boundaries of user-supplied data before processing. This insufficient validation allows input that exceeds expected boundaries to be processed, resulting in an out-of-bounds write condition. The affected components in Acronis DeviceLock DLP and Cyber Protect Cloud Agent do not properly sanitize input, leading to memory corruption that can be exploited for privilege escalation.

Attack Vector

The attack vector for this vulnerability is local, requiring the attacker to have authenticated access to the target Windows system. The exploitation path involves:

1. A local user with low privileges identifies a vulnerable Acronis component
2. The attacker crafts malicious input designed to trigger the improper input validation flaw
3. The crafted input causes an out-of-bounds write in the affected component
4. By controlling the memory corruption, the attacker manipulates execution flow or critical data structures
5. The attacker achieves elevated privileges, potentially gaining SYSTEM-level access

The vulnerability requires no user interaction and has low attack complexity, making exploitation relatively straightforward for an attacker with local access. For detailed technical information, refer to the Acronis Security Advisory SEC-10296.

Detection Methods for CVE-2026-41220

Indicators of Compromise

• Unusual process behavior from Acronis DeviceLock DLP or Cyber Protect Cloud Agent services
• Unexpected privilege escalation events associated with Acronis software components
• Memory corruption or crash dumps originating from Acronis services
• Suspicious access patterns to Acronis component files or registry keys

Detection Strategies

• Monitor for abnormal child processes spawned by Acronis services running with elevated privileges
• Implement endpoint detection rules for out-of-bounds write attempts in Acronis process memory space
• Track Windows security event logs for privilege escalation events (Event ID 4672, 4673) correlated with Acronis process activity
• Deploy behavioral analysis to detect anomalous system calls from Acronis components

Monitoring Recommendations

• Enable detailed logging for Acronis DeviceLock DLP and Cyber Protect Cloud Agent services
• Implement real-time monitoring of privilege changes on endpoints running affected software
• Configure SIEM alerts for suspicious activity patterns associated with local privilege escalation
• Regularly audit installed Acronis software versions to identify unpatched systems

How to Mitigate CVE-2026-41220

Immediate Actions Required

• Update Acronis DeviceLock DLP (Windows) to build 9.0.93212 or later immediately
• Update Acronis Cyber Protect Cloud Agent (Windows) to build 42183 or later
• Audit all Windows endpoints to identify systems running vulnerable Acronis software versions
• Implement the principle of least privilege to limit the impact of potential exploitation

Patch Information

Acronis has released updated builds that address this vulnerability. Organizations should update to the following minimum versions:

• Acronis DeviceLock DLP (Windows): Build 9.0.93212 or later
• Acronis Cyber Protect Cloud Agent (Windows): Build 42183 or later

Refer to the Acronis Security Advisory SEC-10296 for official patch information and download links.

Workarounds

• Restrict local user access to systems running vulnerable Acronis software until patches can be applied
• Implement application whitelisting to prevent unauthorized executables from running alongside Acronis components
• Monitor and restrict access to Acronis service directories and registry keys
• Consider temporary isolation of critical systems running vulnerable versions until remediation is complete

# Verify installed Acronis DeviceLock DLP version on Windows
wmic product where "name like '%DeviceLock%'" get name,version

# Verify installed Acronis Cyber Protect Cloud Agent version
wmic product where "name like '%Cyber Protect%'" get name,version

# Check for running Acronis services
sc query | findstr /i "acronis"