CVE-2026-20434 Memory corruption in MediaTek chipset
A missing bounds check in MediaTek modem firmware allows remote privilege escalation via a rogue base station, requiring user interaction.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-20434?
CVE-2026-20434 is a high-severity memory corruption vulnerability in Mediatek Nr15, published on 2 Mar 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
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 needed for exploitation. Patch ID: MOLY00782946; Issue ID: MSV-4135.
Weakness: CWE-787
Which versions are affected by CVE-2026-20434?
It affects 5 products.
Products include Mediatek Lr12a, Mediatek Lr13, Mediatek Nr15, Mediatek Nr16, Mediatek Nr17.
How do I fix CVE-2026-20434?
Apply the vendor's patch.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-20434 being exploited?
There is no known exploitation of CVE-2026-20434 in the wild and no public exploit code.
Other vulnerabilities in Mediatek Nr15
- CVE-2024-20154 Memory corruption in MT2735, MT6767, MT6768, MT6769, MT6769K, MT6769S, MT6769T, MT6769Z, MT6779, MT6781, MT6783, MT6785, MT6785T, MT6785U, MT6789, MT6833P, MT6853, MT6853T, MT6855, MT6855T, MT6873, MT6875, MT6875T, MT6877, MT6877T, MT6877TT, MT6880, MT6880T, MT6880U, MT6883, MT6885, MT6889, MT6890, MT6891, MT6893, MT8666, MT8673, MT8675, MT8765, MT8766, MT8768, MT8771, MT8781, MT8786, MT8788, MT8788E, MT8789, MT8791T, MT8795T, MT8797, MT8798
- CVE-2024-20039 Memory corruption in MT2731, MT2735, MT2737, MT3967, MT6297, MT6298, MT6739, MT6761, MT6762, MT6762D, MT6762M, MT6763, MT6765, MT6765T, MT6767, MT6768, MT6769, MT6769T, MT6769Z, MT6771, MT6779, MT6781, MT6783, MT6785, MT6785T, MT6785U, MT6789, MT6813, MT6815, MT6833, MT6835, MT6853, MT6855, MT6873, MT6875, MT6875T, MT6877, MT6879, MT6880, MT6883, MT6885, MT6886, MT6889, MT6890, MT6891, MT6893, MT6895, MT6895T, MT6896, MT6897, MT6980, MT6980D, MT6983, MT6985, MT6986, MT6986D, MT6989, MT6990, MT8666, MT8667, MT8673, MT8675, MT8676, MT8765, MT8766, MT8768, MT8781, MT8786, MT8788, MT8791, MT8791T, MT8792, MT8796, MT8797, MT8798
- CVE-2023-32840 Memory corruption in MT2731, MT2735, MT6731, MT6739, MT6761, MT6762, MT6763, MT6765, MT6767, MT6768, MT6769, MT6769T, MT6769Z, MT6771, MT6771T, MT6813, MT6833, MT6833P, MT6835, MT6853, MT6853T, MT6855, MT6873, MT6875, MT6877, MT6877T, MT6878, MT6879, MT6880, MT6883, MT6885, MT6886, MT6889, MT6890, MT6891, MT6893, MT6895, MT6895T, MT6896, MT6897, MT6980, MT6980D, MT6983T, MT6983W, MT6983Z, MT6985, MT6985T, MT6989, MT6990, MT8666, MT8667, MT8673, MT8675, MT8765, MT8766, MT8768, MT8781, MT8786, MT8788, MT8789, MT8791, MT8791T, MT8797, MT8798
- CVE-2025-20727 Memory corruption in MT2735, MT2737, MT6739, MT6761, MT6762, MT6762D, MT6762M, MT6763, MT6765, MT6765T, MT6767, MT6768, MT6769, MT6769K, MT6769S, MT6769T, MT6769Z, MT6771, MT6813, MT6833, MT6833P, MT6835, MT6835T, MT6853, MT6853T, MT6855, MT6855T, MT6873, MT6875, MT6875T, MT6877, MT6877T, MT6877TT, MT6878, MT6878M, MT6879, MT6880, MT6883, MT6885, MT6886, MT6889, MT6890, MT6891, MT6893, MT6895, MT6895TT, MT6896, MT6897, MT6899, MT6980, MT6980D, MT6983, MT6983T, MT6985, MT6985T, MT6989, MT6989T, MT6990, MT6991, MT8666, MT8667, MT8673, MT8675, MT8676, MT8678, MT8765, MT8766, MT8766R, MT8768, MT8771, MT8786, MT8788, MT8788E, MT8791, MT8791T, MT8792, MT8793, MT8795T, MT8797, MT8798, MT8863, MT8873, MT8883, MT8893
- CVE-2025-20725 Memory corruption in MT2735, MT2737, MT6739, MT6761, MT6762, MT6762D, MT6762M, MT6763, MT6765, MT6765T, MT6767, MT6768, MT6769, MT6769K, MT6769S, MT6769T, MT6769Z, MT6771, MT6833, MT6833P, MT6853, MT6853T, MT6855, MT6855T, MT6873, MT6875, MT6875T, MT6877, MT6877T, MT6877TT, MT6879, MT6880, MT6883, MT6885, MT6886, MT6889, MT6890, MT6891, MT6893, MT6895, MT6895TT, MT6896, MT6980, MT6980D, MT6983, MT6983T, MT6985, MT6985T, MT6989, MT6989T, MT6990, MT8666, MT8667, MT8673, MT8675, MT8765, MT8766, MT8766R, MT8768, MT8771, MT8786, MT8788, MT8788E, MT8791, MT8791T, MT8795T, MT8797, MT8798, MT8893
Sources
Also known as A-473385376, ASB-A-473385376, GHSA-q532-r27c-r7m9, M-MOLY00782946.