SB20260720337 - Out-of-bounds write in Linux kernel usb serial driver
Published: July 20, 2026
Security Bulletin ID
SB20260720337
CSH Severity
Medium
Patch available
YES
Number of vulnerabilities
1
Exploitation vector
Physical access
Highest impact
Denial of service
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 1 vulnerability.
1) Out-of-bounds write (CVE-ID: CVE-2026-63899)
CWE-ID: CWE-787 - Out-of-bounds write
CVSSv4: 5.1 [CVSS:4.0/AV:P/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows an attacker with physical access to cause memory corruption.
The vulnerability exists due to memory corruption in the mxuport USB serial driver when handling a malicious USB device that reports a bulk-out endpoint max packet size smaller than eight bytes. An attacker with physical access can attach a crafted device to cause memory corruption.
Remediation
Install update from vendor's website.
References
- https://git.kernel.org/stable/c/086b858b5f5125bc9d967ea2bd825f83d9f8f29d
- https://git.kernel.org/stable/c/2f3661eb2446e1ef593da45e01a3b21a906768ec
- https://git.kernel.org/stable/c/4085f0dbb1ce2251c9a5938d693de6593f0ab2bd
- https://git.kernel.org/stable/c/6c0cf56f00f280d72180bb6ce79741bc787a6269
- https://git.kernel.org/stable/c/b40166b4ef96067620a0f248e74ad9658c8f680c
- https://git.kernel.org/stable/c/be3a1ed4ae51fa8dde57383277d336ce834f2cd9
- https://git.kernel.org/stable/c/ccbec56f2f9af008f1574335cc6a668f16603e47
- https://git.kernel.org/stable/c/e906545641d34fb1a09a65b4b5cfdff40eb09681