CVE-2026-63898
Received Received - Intake

USB Serial mct_u232 Memory Corruption Fix

Publication date: 2026-07-19

Last updated on: 2026-07-19

Assigner: kernel.org

Description
In the Linux kernel, the following vulnerability has been resolved: USB: serial: mct_u232: fix memory corruption with small endpoint The driver overrides the maximum transfer size for a specific device which only accepts 16 byte packets for its 32 byte bulk-out endpoint. Make sure to never increase the maximum transfer size to prevent slab corruption should a malicious device report a smaller endpoint max packet size than expected.

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Meta Information

Published
2026-07-19
Last Modified
2026-07-19
Generated
2026-07-20
AI Q&A
2026-07-19
EPSS Evaluated
N/A
NVD
CVE-2026-63898
EUVD
EUVD-2026-45671

Affected Vendors & Products

Showing 1 associated CPE
Vendor Product Version / Range
linux linux_kernel *

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Exploitability

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CWE ID Description
CWE-UNKNOWN

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Executive Summary

This vulnerability involves a memory corruption issue in the Linux kernel's USB serial driver mct_u232. The driver incorrectly overrides the maximum transfer size for a device that only supports 16-byte packets on a 32-byte bulk-out endpoint. This can lead to slab memory corruption if a malicious device reports a smaller endpoint size than expected.

Detection Guidance

This vulnerability affects the Linux kernel's USB serial driver mct_u232. Detection requires checking kernel logs for USB-related errors or slab corruption warnings. Inspect the driver's behavior with connected USB devices reporting small endpoint sizes. No specific commands are provided in the context.

Impact Analysis

This vulnerability could allow an attacker with physical access to a vulnerable system to trigger memory corruption via a malicious USB device. This might lead to system crashes, data corruption, or potential privilege escalation if exploited successfully.

Compliance Impact

This vulnerability does not directly affect compliance with standards like GDPR or HIPAA as it is a low-level Linux kernel issue related to USB serial driver memory corruption. No evidence suggests it impacts data protection or privacy requirements.

Mitigation Strategies

Apply the Linux kernel patch that resolves this issue. Ensure the mct_u232 driver does not override the maximum transfer size for devices with smaller endpoint sizes. Monitor kernel logs for slab corruption or USB errors.

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