MediaTek Modem OOB Write Remote Priv Esc via Rogue Base Station
CVE-2026-20557 Published on November 2, 2026
In Modem, there is a possible out of bounds write due to a missing bounds check. This could lead to remote escalation of privilege, if a UE has connected to a rogue base station controlled by the attacker, with no additional execution privileges needed. User interaction is not needed for exploitation. Patch ID: MOLY01877236; Issue ID: MSV-9804.
Vulnerability Analysis
Weakness Type
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-2026-20557 has been classified to as a Memory Corruption vulnerability or weakness.
Affected Versions
MediaTek, Inc. MediaTek chipset:- Version MT2716 is affected.
- Version MT6813 is affected.
- Version MT6815 is affected.
- Version MT6835 is affected.
- Version MT6858 is affected.
- Version MT6878 is affected.
- Version MT6881 is affected.
- Version MT6897 is affected.
- Version MT6899 is affected.
- Version MT6982 is affected.
- Version MT6986 is affected.
- Version MT6988 is affected.
- Version MT6991 is affected.
- Version MT6993 is affected.
- Version MT8668 is affected.
- Version MT8676 is affected.
- Version MT8678 is affected.
- Version MT8755 is affected.
- Version MT8775 is affected.
- Version MT8792 is affected.
- Version MT8793 is affected.
- Version MT8863 is affected.
- Version MT8873 is affected.
- Version MT8875 is affected.
- Version MT8883 is affected.