---
id: "CVE-2026-98763"
kind: "vulnerability"
aliases: ["CVE-2026-98763"]
title: "Linux kernel: USB core leaves a freed control endpoint pointer reachable"
severity: "unknown"
cvss: null
epss: null
exploited: false
status: "open"
category: "runtime"
products: []
ecosystems: []
tags: ["linux-kernel", "runtime", "usb"]
not_affected_if: []
published_at: "2026-10-18T16:17:30+00:00"
first_seen_at: "2026-10-23T21:57:16+00:00"
updated_at: "2026-10-25T05:16:43+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-98763", "first_seen_at": "2026-10-23T21:57:16+00:00"}]
---

# Linux kernel: USB core leaves a freed control endpoint pointer reachable

In the Linux kernel USB core, disabling a non-zero control endpoint clears only one direction's pointer, leaving a stale reference to a freed endpoint in the other. The sources do not describe a concrete way for an attacker to trigger it or what they gain from it.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- unknown

## Fix

- unknown

## Timeline

- 2026-10-23T21:57:16+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-98763

## From the sources

In the Linux kernel, the following vulnerability has been resolved:

usb: core: clear both ep_in and ep_out for non-ep0 control endpoints

In usb_enable_endpoint(), non-zero control endpoints (where
usb_endpoint_xfer_control(&ep->desc) is true) populate both
dev->ep_in[epnum] and dev->ep_out[epnum] with the same struct
usb_host_endpoint pointer.

However, usb_disable_endpoint() only clears either dev->ep_out[epnum] or
dev->ep_in[epnum] depending on the direction bit of epaddr when
reset_hardware is set, leaving the opposite direction's array slot
pointing to the disabled/freed endpoint.

Clear both dev->ep_out[epnum] and dev->ep_in[epnum] when disabling a
non-ep0 control endpoint with reset_hardware set, and update the
function kerneldoc accordingly.

Tested in QEMU against Linux 7.3.0-rc3 using dummy_hcd and raw-gadget to
enumerate a USB device with a non-zero control endpoint
(bEndpointAddress 0x01, bmAttributes USB_ENDPOINT_XFER_CONTROL),
verifying that both dev->ep_in[1] and dev->ep_out[1] are cleared when
the interface is disabled.

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_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_