CVE-2026-89621

medium

Description

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.

References

https://git.kernel.org/stable/c/fffcfa367072628c3144cca17d2a3c3c9e50c057

https://git.kernel.org/stable/c/cb38b1f149b7143355b37e86c841acf0076e5c2a

https://git.kernel.org/stable/c/c1c508e8923911cb458234997e55b7a4b9aa066f

https://git.kernel.org/stable/c/bdc6a3af0dd734a326acdb7d6401a3b6a9f4f149

https://git.kernel.org/stable/c/b2c67dc0e30c308647bbd9b9e5d69a44c9d2733d

https://git.kernel.org/stable/c/7c18fb36708a97ff6772825cc087b6d537bbf0d5

https://git.kernel.org/stable/c/2c9a6998c19503626c57a2267bf279e204113079

https://git.kernel.org/stable/c/127de5919820f88a9d55e8371ad4ac49f625f4c5

https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-76533

Details

Source: Mitre, NVD

Published: 2026-09-11

Updated: 2026-09-14

Risk Information

CVSS v2

Base Score: 2.1

Vector: CVSS2#AV:L/AC:L/Au:N/C:P/I:N/A:N

Severity: Low

CVSS v3

Base Score: 5.5

Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

Severity: Medium

EPSS

EPSS: 0.00209