CVE-2026-20409

7.8 HIGH

📋 TL;DR

CVE-2026-20409 is an out-of-bounds write vulnerability in the imgsys component that allows local privilege escalation. Attackers with initial System privilege access can exploit this to gain higher privileges without user interaction. This affects devices using MediaTek chipsets with vulnerable imgsys firmware.

💻 Affected Systems

Products:
  • MediaTek chipset devices with imgsys component
Versions: Specific firmware versions not detailed in advisory; affected versions prior to patch ALPS10363246
Operating Systems: Android-based systems using MediaTek chipsets
Default Config Vulnerable: ⚠️ Yes
Notes: Requires devices with MediaTek chipsets and vulnerable imgsys firmware. Exact device models not specified in provided reference.

⚠️ Risk & Real-World Impact

🔴

Worst Case

Complete system compromise allowing attackers to execute arbitrary code with kernel privileges, install persistent malware, or bypass all security controls.

🟠

Likely Case

Local privilege escalation from System to kernel-level access, enabling further system manipulation and persistence.

🟢

If Mitigated

Limited impact if proper privilege separation and kernel hardening are implemented, though still a serious local vulnerability.

🌐 Internet-Facing: LOW - This is a local privilege escalation requiring initial System access, not directly exploitable over network.
🏢 Internal Only: HIGH - Once an attacker gains System privilege through other means, this provides easy escalation to full system control.

🎯 Exploit Status

Public PoC: ✅ No
Weaponized: UNKNOWN
Unauthenticated Exploit: ✅ No
Complexity: MEDIUM

Exploitation requires existing System privilege access. The missing bounds check suggests straightforward exploitation once initial access is obtained.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: Patch ID: ALPS10363246

Vendor Advisory: https://corp.mediatek.com/product-security-bulletin/February-2026

Restart Required: Yes

Instructions:

1. Contact device manufacturer for firmware updates. 2. Apply patch ALPS10363246. 3. Reboot device. 4. Verify patch installation through firmware version check.

🔧 Temporary Workarounds

Restrict System Privilege Access

android

Limit which applications and users can obtain System privilege to reduce attack surface.

Enable SELinux/AppArmor

linux

Use mandatory access control to contain potential privilege escalation attempts.

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🧯 If You Can't Patch

  • Implement strict application sandboxing and privilege separation
  • Monitor for unusual System privilege usage and privilege escalation attempts

🔍 How to Verify

Check if Vulnerable:

Check firmware version and patch status through device settings or manufacturer tools. Look for imgsys component version.

Check Version:

Manufacturer-specific commands vary; typically through adb: 'adb shell getprop ro.build.fingerprint' or device settings

Verify Fix Applied:

Verify patch ALPS10363246 is applied through firmware update logs or version checks.

📡 Detection & Monitoring

Log Indicators:

  • Kernel panic logs
  • imgsys component crashes
  • unexpected privilege escalation attempts

Network Indicators:

  • Not applicable - local exploit only

SIEM Query:

Search for: 'imgsys' AND ('crash' OR 'panic' OR 'privilege escalation') in system logs

📊 Metadata

CVE ID: CVE-2026-20409
CVSS v3 Score: 7.8 (HIGH)
CVSS Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CWE: CWE-787
Published: February 2, 2026
Last Updated: February 4, 2026

🤖 AI-assisted analysis, reviewed for accuracy

🔗 References

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