CVE-2025-20766 is a vulnerability classified under CWE-457 (Use of Uninitialized Variable) affecting a broad range of MediaTek chipsets including MT2718, MT6739, MT6761, MT6765, MT6768, MT6781, MT6789, MT6833, MT6835, MT6853, MT6855, MT6877, MT6878, MT6879, MT6883, MT6885, MT6886, MT6889, MT6893, MT6895, MT6897, MT6899, MT6983, MT6985, MT6989, MT6991, MT8196, MT8676, MT8678, MT8792, and MT8793. These chipsets are integrated into devices running Android versions 14.0, 15.0, and 16.0. The vulnerability arises from improper input validation in the display subsystem, which leads to memory corruption due to the use of uninitialized variables. This flaw can be exploited locally by an attacker who already possesses System-level privileges, allowing them to escalate privileges further, potentially gaining higher control over the device. The attack does not require user interaction, increasing the risk once System access is obtained. The CVSS v3.1 base score is 7.8, indicating high severity, with vector AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H, meaning local attack vector, low attack complexity, low privileges required, no user interaction, unchanged scope, and high impact on confidentiality, integrity, and availability. No public exploits are known at this time, but the vulnerability is published and patches have been identified internally (Patch ID: ALPS10196993). The issue was reserved in November 2024 and published in December 2025. This vulnerability is critical for devices using these MediaTek chipsets, as it can be leveraged to compromise device security post System-level access.

For European organizations, the impact of CVE-2025-20766 can be significant, especially those relying on Android devices powered by affected MediaTek chipsets. The vulnerability enables local privilege escalation, which can lead to complete device compromise, exposing sensitive corporate data, enabling unauthorized access to internal networks, and potentially facilitating lateral movement within enterprise environments. Confidentiality, integrity, and availability of affected devices are at high risk. This is particularly concerning for sectors with high security requirements such as finance, healthcare, and government agencies. The lack of required user interaction means that once an attacker gains System privileges—possibly through other vulnerabilities or insider threats—they can exploit this flaw to deepen their control. The widespread use of MediaTek chipsets in mid-range and budget devices across Europe increases the attack surface. Additionally, the vulnerability could be leveraged in targeted attacks against high-value individuals or organizations using these devices. The absence of known exploits in the wild currently reduces immediate risk, but the availability of patches and public disclosure increases the urgency for mitigation.

1. Immediate deployment of vendor-supplied patches (Patch ID: ALPS10196993) as soon as they become available is critical. 2. Restrict and monitor System-level privileges on Android devices to minimize the risk of initial compromise that could lead to exploitation. 3. Implement strict application whitelisting and privilege management to prevent unauthorized escalation. 4. Employ endpoint detection and response (EDR) solutions capable of detecting anomalous behavior indicative of privilege escalation attempts. 5. Conduct regular security audits and vulnerability assessments on mobile device fleets to identify unpatched devices. 6. Educate users and administrators about the risks of granting elevated privileges to applications or processes. 7. For organizations deploying custom Android builds, ensure that input validation in the display subsystem is thoroughly tested and hardened. 8. Utilize mobile device management (MDM) solutions to enforce security policies and automate patch management. 9. Monitor threat intelligence sources for any emerging exploit code or attack campaigns targeting this vulnerability. 10. Consider network segmentation and limiting device access to sensitive resources until devices are confirmed patched.