CVE-2026-89622

Kernel memory corruption via stale MCP2221 buffer

Published Sep 11, 2026 · Updated Sep 11, 2026

Write use-after-free in the Linux kernel MCP2221 HID driver allows attackers to corrupt kernel memory through a delayed device report. mcp_i2c_smbus_read() leaves its caller-owned buffer in mcp->rxbuf after completion or timeout, and mcp2221_raw_event() later copies device data through that dangling pointer. Reaching the flaw requires an MCP2221 I2C/SMBus transfer and a delayed or spurious data report after the transfer ends.

CVSS severityUnavailable
Unscored
EPSS probability0.16%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Write use-after-free in the Linux kernel MCP2221 HID driver allows attackers to corrupt kernel memory through a delayed device report. mcp_i2c_smbus_read() leaves its caller-owned buffer in mcp->rxbuf after completion or timeout, and mcp2221_raw_event() later copies device data through that dangling pointer. Reaching the flaw requires an MCP2221 I2C/SMBus transfer and a delayed or spurious data report after the transfer ends.

The record

CVE
CVE-2026-89622
Published
Sep 11, 2026
Updated
Sep 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
Unavailable
Attack vector
Unavailable
Privileges
Unavailable

Timeline

How it unfolded

  1. Sep 11, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 11, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=5.7
  2. Affected versionversion=67a95c21463d066060b0f66d65a75d45bb386ffb <03c34309eb1bce1b3b5f7c4a94b703f419120383
  3. Affected versionversion=67a95c21463d066060b0f66d65a75d45bb386ffb <968546b676d992dd1da3e057d40598231f725996
  4. Affected versionversion=67a95c21463d066060b0f66d65a75d45bb386ffb <db2333f88729c8aae062cb171ed058725ff5c901

What conditions does exploitation require?

Attack vectorUnavailable in this record.
Required privilegesUnavailable in this record.

What is affected?

The Linux Kernel Organization · Linuxversion=5.7; version=67a95c21463d066060b0f66d65a75d45bb386ffb <03c34309eb1bce1b3b5f7c4a94b703f419120383; version=67a95c21463d066060b0f66d65a75d45bb386ffb <968546b676d992dd1da3e057d40598231f725996; version=67a95c21463d066060b0f66d65a75d45bb386ffb <db2333f88729c8aae062cb171ed058725ff5c901

Published CVSS scores

No CVSS assessment is available in this record.

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
VectorUnavailable
PrivilegesUnavailable
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

No sourced classifications are available.

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo