CVE-2026-80765
Received Received - Intake

HID Descriptor Length Validation Flaw in Linux Kernel

Publication date: 2026-09-04

Last updated on: 2026-09-04

Assigner: kernel.org

Description
In the Linux kernel, the following vulnerability has been resolved: HID: hyperv: validate initial device info bounds The Hyper-V synthetic HID host supplies SYNTH_HID_INITIAL_DEVICE_INFO messages that contain a HID descriptor followed by the report descriptor bytes. mousevsc_on_receive_device_info() trusts bLength and wDescriptorLength without checking that the received packet contains both byte ranges. A malformed host or backend message can therefore make the guest read past the received VMBus packet while copying the report descriptor. Pass the received initial-device-info size into the parser and reject descriptor lengths that exceed the packet. Impact: A malicious Hyper-V host or backend can crash a guest by sending a short initial device-info message with an oversized HID report descriptor length.

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Meta Information

Published
2026-09-04
Last Modified
2026-09-04
Generated
2026-09-04
AI Q&A
2026-09-04
EPSS Evaluated
N/A
NVD
CVE-2026-80765
EUVD
EUVD-2026-71408

Affected Vendors & Products

Showing 1 associated CPE
Vendor Product Version / Range
linux linux_kernel *

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Exploitability

CWE
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KEV
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CWE ID Description
CWE-UNKNOWN

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Executive Summary

This vulnerability in the Linux kernel involves the Hyper-V synthetic HID host sending malformed messages containing HID descriptor and report descriptor bytes. The guest system trusts the descriptor lengths without verifying if the packet contains both ranges, allowing a malicious host to crash the guest by sending a short message with an oversized report descriptor length.

Detection Guidance

This vulnerability is specific to Linux kernel HID handling for Hyper-V devices. Detection requires checking kernel logs for crashes or errors related to HID device initialization. Monitor dmesg or journalctl for messages about mousevsc_on_receive_device_info or Hyper-V HID errors.

Impact Analysis

A malicious Hyper-V host or backend could exploit this to crash a guest system running the vulnerable Linux kernel, leading to denial of service or potential data loss if the guest fails to recover properly.

Mitigation Strategies

Update the Linux kernel to the latest patched version. If immediate patching is not possible, disable Hyper-V synthetic HID devices if not required. Monitor vendor advisories for kernel updates addressing this issue.

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