# CVE-2026-89621

## Summary

- **CVE ID:** CVE-2026-89621
- **Severity:** UNKNOWN
- **CVSS Score:** 0
- **CWE:** N/A
- **Published:** Sep 11, 2026
- **Last Modified:** Sep 16, 2026

## 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.

## Affected Products

- Linux — Linux (67a95c21463d066060b0f66d65a75d45bb386ffb)
- Linux — Linux (5.7)
- Linux — Linux (0)
- Linux — Linux (6.12.109)
- Linux — Linux (6.18.50)
- Linux — Linux (7.2.4)
- Linux — Linux (7.3-rc1)
- Linux — Linux (5.10.270)
- Linux — Linux (5.15.221)
- Linux — Linux (6.1.188)
- Linux — Linux (6.6.157)

## References

- [CNA](https://git.kernel.org/stable/c/bdc6a3af0dd734a326acdb7d6401a3b6a9f4f149)
- [CNA](https://git.kernel.org/stable/c/127de5919820f88a9d55e8371ad4ac49f625f4c5)
- [CNA](https://git.kernel.org/stable/c/7c18fb36708a97ff6772825cc087b6d537bbf0d5)
- [CNA](https://git.kernel.org/stable/c/2c9a6998c19503626c57a2267bf279e204113079)
- [CNA](https://git.kernel.org/stable/c/cb38b1f149b7143355b37e86c841acf0076e5c2a)
- [CNA](https://git.kernel.org/stable/c/b2c67dc0e30c308647bbd9b9e5d69a44c9d2733d)
- [CNA](https://git.kernel.org/stable/c/fffcfa367072628c3144cca17d2a3c3c9e50c057)
- [CNA](https://git.kernel.org/stable/c/c1c508e8923911cb458234997e55b7a4b9aa066f)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.22%
- **EPSS Percentile:** 12.6

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-17._