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.
Advisories
Source ID Title
Debian DLA Debian DLA DLA-4817-1 linux-6.12 security update
Debian DLA Debian DLA DLA-4841-1 linux security update
Debian DSA Debian DSA DSA-6528-1 linux security update
Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Mon, 14 Sep 2026 12:30:00 +0000


Sat, 12 Sep 2026 15:45:00 +0000

Type Values Removed Values Added
Weaknesses CWE-119
CWE-200

Sat, 12 Sep 2026 12:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-125
References
Metrics threat_severity

None

cvssV3_1

{'score': 4.3, 'vector': 'CVSS:3.1/AV:P/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N'}

threat_severity

Moderate


Sat, 12 Sep 2026 09:30:00 +0000

Type Values Removed Values Added
Weaknesses CWE-119
CWE-200

Fri, 11 Sep 2026 23:45:00 +0000

Type Values Removed Values Added
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.
Title HID: mcp2221: validate report size in mcp2221_raw_event()
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References

Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-10-19T08:49:53.686Z

Reserved: 2026-09-11T19:38:34.736Z

Link: CVE-2026-89621

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-09-11T20:19:47.397

Modified: 2026-10-19T09:17:58.880

Link: CVE-2026-89621

cve-icon Redhat

Severity : Moderate

Publid Date: 2026-09-11T19:45:19Z

Links: CVE-2026-89621 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-09-15T21:15:14Z

Weaknesses