CVE-2026-20509: CWE-121 Stack-based Buffer Overflow in MediaTek, Inc. MediaTek chipset
Description
CVE-2026-20509 is a stack-based buffer overflow vulnerability in the Power HAL component of MediaTek chipsets. The flaw arises from a missing bounds check, allowing an out-of-bounds write. Exploitation requires local access with System privileges but does not require user interaction. This vulnerability could lead to escalation of privileges and impacts confidentiality, integrity, and availability. A patch identified as ALPS11165543 addresses this issue.
CVSS v3.1
Score 6.7medium
Affected software
MediaTek, Inc.
MediaTek chipset
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
This vulnerability (CWE-121) in MediaTek chipsets' Power HAL involves a missing bounds check that results in a stack-based buffer overflow. An attacker with existing System privileges can exploit this flaw locally without user interaction to escalate privileges further. The vulnerability affects multiple MediaTek chipset versions explicitly listed. The CVSS v3.1 base score is 6.7, indicating a medium severity with high impact on confidentiality, integrity, and availability. The vendor has assigned Patch ID ALPS11165543 for remediation.
Potential Impact
Successful exploitation allows a local attacker with System privileges to perform an out-of-bounds write, potentially escalating privileges further and compromising system confidentiality, integrity, and availability. No user interaction is required, increasing the risk in environments where an attacker already has elevated access.
Mitigation Recommendations
A patch identified as ALPS11165543 is available to address this vulnerability. Users and vendors should apply this official fix to affected MediaTek chipset versions to remediate the issue. Since this is not a cloud service, remediation depends on applying the patch to the affected devices.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- MediaTek
- Date Reserved
- 2025-11-03T01:30:59.029Z
- State
- PUBLISHED
Threat ID: 6a9e1c72acd9273b49c51d75
Added to database: 09/07/2026, 02:07:46 UTC
Last enriched: 09/15/2026, 01:21:10 UTC
Last updated: 10/21/2026, 13:20:20 UTC
Views: 79
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