CVE-2026-80765: HID: hyperv: validate initial device info bounds
HID: hyperv: validate initial device info bounds
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 6.6.157.1-1
Event History
Frequently Asked Questions
Which systems are exposed to this issue?
Linux guests using the Hyper-V synthetic HID device are exposed when their Hyper-V host or backend can send crafted SYNTH_HID_INITIAL_DEVICE_INFO messages. The described attacker is a malicious Hyper-V host or backend.
What does exploitation require?
An attacker must be able to send a short initial device-info message with an oversized HID report descriptor length to the guest. This causes the guest to read beyond the received VMBus packet while copying the report descriptor.
What is the expected impact?
A malicious host or backend can crash the affected Linux guest. The provided information does not describe privilege escalation, data disclosure, or guest-to-host impact.
How can I tell whether a system has the fix?
The fix passes the received initial-device-info size into the parser and rejects descriptor lengths that exceed the packet. Check whether the kernel source or applied stable patch set includes one of the referenced commits.