SB20260720277 - Improper input validation in Linux kernel usb serial driver

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Main Vulnerability Database SB20260720277

SB20260720277 - Improper input validation in Linux kernel usb serial driver

Published: July 20, 2026

Security Bulletin ID SB20260720277
CSH Severity
Medium
Patch available
YES
Number of vulnerabilities 1
Exploitation vector Physical access
Highest impact Denial of service

Breakdown by Severity

Medium 100%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 1 vulnerability.


1) Improper input validation (CVE-ID: CVE-2026-63956)

CWE-ID: CWE-20 - Improper input validation

CVSSv4: 5.2 [CVSS:4.0/AV:P/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N]


The vulnerability allows an attacker with physical access to cause a denial of service or corrupt memory.

The vulnerability exists due to improper input validation in the cypress_m8 USB serial driver when processing a malicious USB device with a too-small interrupt-out endpoint max packet size. An attacker with physical access can connect a specially crafted USB device to cause a denial of service or corrupt memory.

The issue can be triggered if a device reports an interrupt-out endpoint max packet size smaller than eight bytes.


Remediation

Install update from vendor's website.

References