VDB-343695 · CVE-2026-20403 · GCVE-0-2026-20403

MediaTek MT8893 Base Station out-of-bounds write

CVSS Meta Temp Score CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.	Current Exploit Price (≈) Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.	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.
5.0	$0-$5k	0.00

Summaryinfo

A vulnerability identified as critical has been detected in MediaTek MT2735, MT2737, MT6813, MT6815, MT6833, MT6835, MT6853, MT6855, MT6873, MT6875, MT6877, MT6878, MT6879, MT6880, MT6883, MT6885, MT6886, MT6889, MT6890, MT6891, MT6893, MT6895, MT6896, MT6897, MT6899, MT6980, MT6983, MT6985, MT6989, MT6990, MT6991, MT6993, MT8673, MT8675, MT8676, MT8771, MT8791, MT8791T, MT8795T, MT8797, MT8798 and MT8893. Affected by this vulnerability is an unknown functionality of the component Base Station Handler. Performing a manipulation results in out-of-bounds write. This vulnerability is known as CVE-2026-20403. Remote exploitation of the attack is possible. No exploit is available. It is recommended to apply a patch to fix this issue.

Detailsinfo

A vulnerability, which was classified as problematic, was found in MediaTek MT2735, MT2737, MT6813, MT6815, MT6833, MT6835, MT6853, MT6855, MT6873, MT6875, MT6877, MT6878, MT6879, MT6880, MT6883, MT6885, MT6886, MT6889, MT6890, MT6891, MT6893, MT6895, MT6896, MT6897, MT6899, MT6980, MT6983, MT6985, MT6989, MT6990, MT6991, MT6993, MT8673, MT8675, MT8676, MT8771, MT8791, MT8791T, MT8795T, MT8797, MT8798 and MT8893. This affects some unknown functionality of the component Base Station Handler. The manipulation with an unknown input leads to a out-of-bounds write vulnerability. CWE is classifying the issue as CWE-787. The product writes data past the end, or before the beginning, of the intended buffer. This is going to have an impact on availability. The summary by CVE is:

In Modem, there is a possible system crash due to a missing bounds check. This could lead to remote denial of service, 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: MOLY01689254 (Note: For N15 and NR16) / MOLY01689259 (Note: For NR17 and NR17R); Issue ID: MSV-4843.

It is possible to read the advisory at corp.mediatek.com. This vulnerability is uniquely identified as CVE-2026-20403 since 11/03/2025. The exploitability is told to be difficult. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. The technical details are unknown and an exploit is not publicly available.

Applying a patch is able to eliminate this problem.

Be aware that VulDB is the high quality source for vulnerability data.

Productinfo

Type

Chip Software

Vendor

MediaTek

Name

License

commercial

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.1
VulDB Meta Temp Score: 5.0

VulDB Base Score: 3.7
VulDB Temp Score: 3.6
VulDB Vector: 🔒
VulDB Reliability: 🔍

ADP CISA Base Score: 6.5
ADP CISA Vector: 🔒

CVSSv2info

AV	AC	Au	C	I	A
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💳	💳	💳	💳	💳	💳
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Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
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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

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Today	Unlock	Unlock	Unlock	Unlock

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Patch
Status: 🔍

0-Day Time: 🔒

Timelineinfo

11/03/2025 CVE reserved
02/02/2026 +91 days Advisory disclosed
02/02/2026 +0 days VulDB entry created
02/17/2026 +15 days VulDB entry last update

Sourcesinfo

Advisory: corp.mediatek.com
Status: Confirmed

CVE: CVE-2026-20403 (🔒)
GCVE (CVE): GCVE-0-2026-20403
GCVE (VulDB): GCVE-100-343695

Entryinfo

Created: 02/02/2026 10:18
Updated: 02/17/2026 20:46
Changes: 02/02/2026 10:18 (54), 02/04/2026 16:09 (1), 02/17/2026 20:46 (11)
Complete: 🔍
Cache ID: 216::103