SB20261022383 - Use-after-free in Linux kernel usb class driver

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Main Vulnerability Database SB20261022383

SB20261022383 - Use-after-free in Linux kernel usb class driver

Published: October 22, 2026

Security Bulletin ID SB20261022383
CSH Severity
Low
Patch available
YES
Number of vulnerabilities 1
Exploitation vector Local access
Highest impact Denial of service

Breakdown by Severity

Low 100%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 1 vulnerability.


1) Use-after-free (CVE-ID: CVE-2026-98773)

CWE-ID: CWE-416 - Use After Free

CVSSv4: 5.7 [CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]


The vulnerability allows a local user to cause a denial of service by potentially crashing the kernel.

The vulnerability exists due to a use-after-free in the Linux kernel USB CDC ACM driver when port shutdown overlaps with device disconnection. A local user can trigger concurrent port shutdown and device disconnection to cause resubmitted USB request blocks to access freed DMA buffers in acm_ctrl_irq() or acm_read_bulk_callback(), potentially crashing the kernel.

The described USB request resubmission occurs when the ALWAYS_POLL_CTRL quirk is set.


Remediation

Install update from vendor's website.

References