CVE-2026-89621

In the Linux kernel, the following vulnerability has been resolved:

HID: mcp2221: validate report size in mcp2221 raw event()

mcp2221 raw event() never validates the size of incoming HID reports. In the MCP2221 I2C GET DATA path it trusts the device-supplied data[3] as the copy length without checking that 4 + data[3] bytes actually exist in the received report. A malicious or misbehaving USB device can send a short report with a large data[3], causing the memcpy to read past the valid report data in the HID transfer buffer and leak uninitialized kernel memory back to userspace through the I2C/SMBus read path.

Add a minimum size check at entry and validate that the source range fits within the received report before the copy.