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CVE-2026-64331

In the Linux kernel, the following vulnerability has been resolved: usbip: vudc: fix NULL deref in vep_dequeue() vep_alloc_request() wasn't initializing vrequest->udc, so cancellations on the Fun…

Published Jul 25, 2026EPSS 0.12%

Overview

CVE-2026-64331 is a known-severity vulnerability. It was published on July 25, 2026.

Technical description

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

usbip: vudc: fix NULL deref in vep_dequeue()

vep_alloc_request() wasn't initializing vrequest->udc, so cancellations

on the FunctionFS AIO path were arriving in vep_dequeue without a valid

UDC reference.

Since vrequest->udc is never actually properly used anywhere, we opt to

remove it, and update vep_dequeue to obtain a reference to the udc with

ep_to_vudc(), consistent with the other vep_ ops.

AFAICT this bug has existed for ~10 years. Seems that nobody has really

stressed the FunctionFS AIO path on usbip's vudc.

I tested this fix in a QEMU aarch64 guest driving FunctionFS endpoints

via AIO. Before the fix, running `usbip attach` from the host would

cause the guest to oops with the following backtrace:

Call trace:

vep_dequeue+0x1c/0xe4 (P)

usb_ep_dequeue+0x14/0x20

ffs_aio_cancel+0x24/0x34

__arm64_sys_io_cancel+0xb0/0x124

do_el0_svc+0x68/0x100

el0_svc+0x18/0x5c

el0t_64_sync_handler+0x98/0xdc

el0t_64_sync+

Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

Frequently asked questions

What is CVE-2026-64331?

CVE-2026-64331 is a known-severity vulnerability. It was published on July 25, 2026.

How severe is CVE-2026-64331?

CVSS score information is not yet available for this vulnerability. Check back as the CVE record is updated by NVD analysts.

How do I fix or remediate CVE-2026-64331?

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

How can CyberStrike help with CVE-2026-64331?

CyberStrike is an open-source, AI-augmented pentesting engine. Rather than flag a version number, it tests whether an issue like CVE-2026-64331 is actually reachable in your own applications and APIs, then verifies each finding before reporting it. That tells you if the weakness is a real, exploitable risk in your environment or a false positive you can safely deprioritize.