CVE-2026-80765

What the bug is

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.

Where it lives

The fix touches these files. If the subsystem is one you do not use, the practical exposure is lower, though the package is still the vulnerable one.

drivers/hid/hid-hyperv.c

What this is

Hyper-V/Azure CORE AND DRIVERSMAINTAINERS section matched on drivers/hid/hid-hyperv.c · linux-hyperv@vger.kernel.org · Supported

Kernel module

hid_hyperv

Check it on the machine

grep -wE 'CONFIG_HID|CONFIG_HID_HYPERV_MOUSE|CONFIG_HID_SUPPORT' /boot/config-$(uname -r)

Reads the booted kernel's own configuration, on the machine and nowhere else. =y is built in, =m is a module, and an is not set line means the code is not there.

lsmod | grep -w hid_hyperv

Prints a line if that module is loaded right now, and nothing if it is not. One that is not loaded can still be loaded later by anything that needs it.

Show whether Debian builds this, per release

Debian builds this, but not on every flavour. At least one release below builds the code on some of its kernel flavours and not on others, so the answer depends on the architecture and flavour installed.

• bookwormMnot built on arm64/cloud-arm64, armhf/armmp, armhf/armmp-lpae, armhf/rt/armmp, ppc64el/powerpc64le
• trixieMnot built on arm64/cloud-arm64, armel/rpi, armhf/armmp, armhf/armmp-lpae, armhf/rt/armmp, ppc64el/powerpc64le, ppc64el/powerpc64le-64k, riscv64/riscv64, s390x/s390x
• forky, sidMnot built on amd64/cloud-amd64, arm64/cloud-arm64, armhf/armmp, armhf/armmp-lpae, loong64/loong64, ppc64el/powerpc64le, ppc64el/powerpc64le-64k, riscv64/riscv64, s390x/s390x
• bookworm · linux-6.12Mnot built on arm64/cloud-arm64, armhf/armmp, armhf/armmp-lpae, armhf/rt/armmp, ppc64el/powerpc64le, ppc64el/powerpc64le-64k

M

a module where it is built at all; some flavours do not build it

Build switches

CONFIG_HID, CONFIG_HID_HYPERV_MOUSE, CONFIG_HID_SUPPORT

Reads as

all on means the file is compiled; any one off means it is not.

From the configuration Debian publishes for every kernel flavour it builds. It covers only the architectures Debian ships a linux-config package for, and nothing about a kernel you built yourself. Debian's own status above stays authoritative about the source package.MAINTAINERS kbuild Makefiles Debian linux-config packages

Signals

Published

2026-09-04 (44 days ago)source

CVSS

no vector published, unrated

Attack vector

not published

EPSS

0.19%, higher than 8.6% of all CVEssource

CISA KEV

not listedthe KEV catalogue

Debian urgency

not yet assignedsource

Subsystem

drivers/hid

Upstream fixes

The versions the CNA records as introducing and fixing this, and the commit for each. source

Introduced	Fixed in	Commit
3.3	5.10.267	e0d5d3e45e14
3.3	5.15.218	390d3d9c52a7
3.3	6.1.185	8614c043b11c
3.3	6.6.154	334271d3812a
3.3	6.12.106	f84d777574b7
3.3	6.18.47	608f8fd8c0f7
3.3	7.1.11	2529737763cb
3.3	7.2.1	c894143c508a
3.3	7.3	934b7778aa7b

Debian advisories