#VU123452 Out-of-bounds write in MediaTek products - CVE-2026-20434

Vulnerability identifier: #VU123452

Vulnerability risk: Low

CVSSv4.0: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear

CVE-ID: CVE-2026-20434

CWE-ID: CWE-787

Exploitation vector: Local access

Exploit availability: No public exploit available

Vulnerable software:
MT2735
MT2737
MT6739
MT6761
MT6762
MT6762D
MT6762M
MT6763
MT6765
MT6765T
MT6767
MT6768
MT6769
MT6769K
MT6769S
MT6769T
MT6769Z
MT6771
MT6783
MT6785T
MT6785U
MT6789
MT6833
MT6833P
MT6835
MT6835T
MT6855
MT6855T
MT6875T
MT6877T
MT6877TT
MT6878
MT6878M
MT6879
MT6880
MT6886
MT6890
MT6895
MT6895TT
MT6896
MT6897
MT6899
MT6980
MT6980D
MT6983
MT6983T
MT6985
MT6985T
MT6989
MT6989T
MT6990
MT6991
MT8666
MT8667
MT8668
MT8673
MT8675
MT8676
MT8678
MT8755
MT8765
MT8766
MT8766R
MT8768
MT8771
MT8781
MT8786
MT8788
MT8788E
MT8789
MT8791
MT8791T
MT8792
MT8793
MT8795T
MT8798
MT8863
MT8873
MT8883
MT8893
MT6779
MT6781
MT6785
MT6853
MT6853T
MT6873
MT6875
MT6877
MT6883
MT6885
MT6889
MT6891
MT6893
MT8797

Software vendor:
MediaTek

The vulnerability allows a local application to execute arbitrary code.

The vulnerability exists due to a missing bounds check . A local application can execute arbitrary code.

Install security update from vendor's website.

• https://corp.mediatek.com/product-security-bulletin/March-2026