MediaTek MT8893 Modem out-of-bounds write

CVSS Meta Temp Score
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CTI Interest Score
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9.5$0-$5k0.81

Summaryinfo

A vulnerability marked as very critical has been reported in MediaTek MT2716, MT2735, MT2737, MT6739, MT6761, MT6762, MT6763, MT6765, MT6767, MT6768, MT6769, MT6771, MT6779, MT6781, MT6783, MT6785, MT6789, MT6813, MT6833, MT6835, MT6853, MT6855, MT6858, MT6873, MT6875, MT6877, MT6878, MT6879, MT6880, MT6881, MT6883, MT6885, MT6886, MT6889, MT6890, MT6891, MT6893, MT6895, MT6896, MT6897, MT6899, MT6980, MT6982VB, MT6983, MT6985, MT6986, MT6988, MT6989, MT6990, MT6991, MT6993, MT8666, MT8667, MT8668, MT8673, MT8675, MT8676, MT8678, MT8755, MT8765, MT8766, MT8766R, MT8768, MT8771, MT8775, MT8781, MT8786, MT8788, MT8788E, MT8789, MT8791, MT8791T, MT8792, MT8793, MT8795T, MT8796, MT8797, MT8798, MT8863, MT8873, MT8883 and MT8893. This impacts an unknown function of the component Modem. The manipulation leads to out-of-bounds write. This vulnerability is listed as CVE-2026-20499. The attack may be initiated remotely. There is no available exploit. It is suggested to install a patch to address this issue.

Detailsinfo

A vulnerability was found in MediaTek MT2716, MT2735, MT2737, MT6739, MT6761, MT6762, MT6763, MT6765, MT6767, MT6768, MT6769, MT6771, MT6779, MT6781, MT6783, MT6785, MT6789, MT6813, MT6833, MT6835, MT6853, MT6855, MT6858, MT6873, MT6875, MT6877, MT6878, MT6879, MT6880, MT6881, MT6883, MT6885, MT6886, MT6889, MT6890, MT6891, MT6893, MT6895, MT6896, MT6897, MT6899, MT6980, MT6982VB, MT6983, MT6985, MT6986, MT6988, MT6989, MT6990, MT6991, MT6993, MT8666, MT8667, MT8668, MT8673, MT8675, MT8676, MT8678, MT8755, MT8765, MT8766, MT8766R, MT8768, MT8771, MT8775, MT8781, MT8786, MT8788, MT8788E, MT8789, MT8791, MT8791T, MT8792, MT8793, MT8795T, MT8796, MT8797, MT8798, MT8863, MT8873, MT8883 and MT8893. It has been rated as very critical. This issue affects an unknown code of the component Modem. The manipulation with an unknown input leads to a out-of-bounds write vulnerability. Using CWE to declare the problem leads to CWE-787. The product writes data past the end, or before the beginning, of the intended buffer. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

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: MOLY01857954; Issue ID: MSV-8247.

The advisory is shared at mediatek.com. The identification of this vulnerability is CVE-2026-20499 since 11/03/2025. The exploitation is known to be easy. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. Neither technical details nor an exploit are publicly available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 11/02/2026).

Applying the patch MOLY01857954 is able to eliminate this problem.

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

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Vendor

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License

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 10.0
VulDB Meta Temp Score: 9.5

VulDB Base Score: 10.0
VulDB Temp Score: 9.5
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Out-of-bounds write
CWE: CWE-787 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Patch
Status: 🔍

0-Day Time: 🔒

Patch: MOLY01857954

Timelineinfo

11/03/2025 CVE reserved
11/02/2026 +364 days Advisory disclosed
11/02/2026 +0 days VulDB entry created
11/02/2026 +0 days VulDB entry last update

Sourcesinfo

Advisory: mediatek.com
Status: Confirmed

CNA: MediaTek
CVE: CVE-2026-20499 (🔒)

GCVE (CVE): GCVE-0-2026-20499
GCVE (VulDB): GCVE-100-429713

Entryinfo

Created: 11/02/2026 03:58
Changes: 11/02/2026 03:58 (54)
Complete: 🔍
Cache ID: 216::103

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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