---
title: "CVE-2026-89622: Linux kernel HID mcp2221 - Use After Free"
description: "Linux kernel HID mcp2221 contains a use-after-free caused by not clearing the rxbuf pointer after I2C/SMBus transfer completion, letting attackers cause memory corruption via delayed device reports, exploit requires device interaction."
url: https://panop.io/threat-heartbeat/CVE-2026-89622/
---

# CVE-2026-89622 Linux kernel HID mcp2221 - Use After Free

Linux kernel HID mcp2221 contains a use-after-free caused by not clearing the rxbuf pointer after I2C/SMBus transfer completion, letting attackers cause memory corruption via delayed device reports, exploit requires device interaction.

CVSS base score 7.8 /10

High

CISA KEV

Not listed

Public exploit

None known

EPSS

0.16% chance of exploitation in 30 days

[View the NVD record ↗](https://nvd.nist.gov/vuln/detail/CVE-2026-89622)

## Details

Type

Use After Free

CVSS vector

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

Published

11 September 2026

Updated

15 October 2026

## Vendor fix

Update to the latest Linux kernel version containing the fix.

Patching closes this CVE. It does not tell you which of your systems run the affected version, or what else is exposed alongside them.

## References

- [https://nvd.nist.gov/vuln/detail/CVE-2026-89622](https://nvd.nist.gov/vuln/detail/CVE-2026-89622)
- [https://git.kernel.org/stable/c/03c34309eb1bce1b3b5f7c4a94b703f419120383](https://git.kernel.org/stable/c/03c34309eb1bce1b3b5f7c4a94b703f419120383)
- [https://git.kernel.org/stable/c/968546b676d992dd1da3e057d40598231f725996](https://git.kernel.org/stable/c/968546b676d992dd1da3e057d40598231f725996)
- [https://git.kernel.org/stable/c/db2333f88729c8aae062cb171ed058725ff5c901](https://git.kernel.org/stable/c/db2333f88729c8aae062cb171ed058725ff5c901)
- [https://git.kernel.org/stable/c/d6c6b293173c0ea87189501cbd77e8fa677814a1](https://git.kernel.org/stable/c/d6c6b293173c0ea87189501cbd77e8fa677814a1)

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## What this record can't tell you

- Whether you run the affected software, and where
- Whether an attacker can actually reach and exploit it
- The misconfigurations that never get a CVE number
- What it would cost the business, ranked into what to fix first

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