Integer Overflow OOB Write in Mediatek Secure Boot
CVE-2026-20446 Published on April 7, 2026
In sec boot, there is a possible out of bounds write due to an integer overflow. This could lead to local denial of service, if an attacker has physical access to the device, with User execution privileges needed. User interaction is not needed for exploitation. Patch ID: ALPS09963054; Issue ID: MSV-3899.
Vulnerability Analysis
CVE-2026-20446 is exploitable with physical access, and requires small amount of user privileges. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have no impact on confidentiality and integrity, and a high impact on availability.
Weakness Types
What is a Memory Corruption Vulnerability?
The software writes data past the end, or before the beginning, of the intended buffer. Typically, this can result in corruption of data, a crash, or code execution. The software may modify an index or perform pointer arithmetic that references a memory location that is outside of the boundaries of the buffer. A subsequent write operation then produces undefined or unexpected results.
CVE-2026-20446 has been classified to as a Memory Corruption vulnerability or weakness.
Integer Overflow or Wraparound
The software performs a calculation that can produce an integer overflow or wraparound, when the logic assumes that the resulting value will always be larger than the original value. This can introduce other weaknesses when the calculation is used for resource management or execution control. An integer overflow or wraparound occurs when an integer value is incremented to a value that is too large to store in the associated representation. When this occurs, the value may wrap to become a very small or negative number. While this may be intended behavior in circumstances that rely on wrapping, it can have security consequences if the wrap is unexpected. This is especially the case if the integer overflow can be triggered using user-supplied inputs. This becomes security-critical when the result is used to control looping, make a security decision, or determine the offset or size in behaviors such as memory allocation, copying, concatenation, etc.
Affected Versions
MediaTek, Inc. MediaTek chipset Version MT6813 is affected by CVE-2026-20446Exploit Probability
EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.