MediaTek MT8893 Modem out-of-bounds write

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
9.5$0-$5k0.00-

Summaryinfo

A vulnerability was found in MediaTek MT2716, MT2735, MT2737, MT6813, MT6815, MT6833, MT6835, MT6853, MT6855, MT6858, MT6873, MT6875, MT6877, MT6878, MT6879, MT6880, MT6881, MT6883, MT6885, MT6886, MT6889, MT6890, MT6891, MT6893, MT6895, MT6896, MT6897, MT6899, MT6980, MT6982, MT6983, MT6985, MT6986, MT6988, MT6989, MT6990, MT6991, MT6993, MT8668, MT8676, MT8678, MT8755, MT8771, MT8775, MT8791, MT8791T, MT8792, MT8793, MT8796, MT8797, MT8798, MT8863, MT8873, MT8875, MT8883 and MT8893. It has been classified as very critical. The affected element is an unknown function of the component Modem. This manipulation causes out-of-bounds write. This vulnerability is handled as CVE-2026-20556. The attack can be initiated remotely. There is not any exploit available. It is suggested to install a patch to address this issue.

Detailsinfo

A vulnerability was found in MediaTek MT2716, MT2735, MT2737, MT6813, MT6815, MT6833, MT6835, MT6853, MT6855, MT6858, MT6873, MT6875, MT6877, MT6878, MT6879, MT6880, MT6881, MT6883, MT6885, MT6886, MT6889, MT6890, MT6891, MT6893, MT6895, MT6896, MT6897, MT6899, MT6980, MT6982, MT6983, MT6985, MT6986, MT6988, MT6989, MT6990, MT6991, MT6993, MT8668, MT8676, MT8678, MT8755, MT8771, MT8775, MT8791, MT8791T, MT8792, MT8793, MT8796, MT8797, MT8798, MT8863, MT8873, MT8875, MT8883 and MT8893. It has been declared as very critical. Affected by this vulnerability is an unknown code block of the component Modem. The manipulation with an unknown input leads to a out-of-bounds write vulnerability. The CWE definition for the vulnerability is CWE-787. The product writes data past the end, or before the beginning, of the intended buffer. As an impact it is known to affect 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: MOLY01876662; Issue ID: MSV-9833.

The advisory is shared at mediatek.com. This vulnerability is known as CVE-2026-20556 since 11/03/2025. The exploitation appears to be easy. The attack can be launched remotely. The exploitation doesn't need any form of authentication. 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 MOLY01876662 is able to eliminate this problem.

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

Productinfo

Type

Vendor

Name

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: MOLY01876662

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-2026-20556 (🔒)

GCVE (CVE): GCVE-0-2026-20556
GCVE (VulDB): GCVE-100-429721

Entryinfo

Created: 11/02/2026 04:00
Changes: 11/02/2026 04:00 (54)
Complete: 🔍
Cache ID: 216::103

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

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