SB20260720336 - Out-of-bounds write in Linux kernel usb serial driver
Published: July 20, 2026
Security Bulletin ID
SB20260720336
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-2026-63898)
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 mct_u232 USB serial driver when handling a malicious USB device that reports a smaller endpoint maximum packet size than expected. An attacker with physical access can connect a specially crafted USB device to cause memory corruption.
Remediation
Install update from vendor's website.
References
- https://git.kernel.org/stable/c/39e295a91e80f3b91f61c7ada2bde434dcaba20d
- https://git.kernel.org/stable/c/57f332af1745014cd7e40414814ffaa6bc7d3b5b
- https://git.kernel.org/stable/c/6cb48f8890f9b2051d7c34823057296a536a31c5
- https://git.kernel.org/stable/c/90dbad14b109e5fdfb4934ff61e561d11ba3742d
- https://git.kernel.org/stable/c/915b36d701950503c4ea0f6e314b10868e59fce3
- https://git.kernel.org/stable/c/94edbbc5fe00d03cfe1d4e690d7d2cd36317a935
- https://git.kernel.org/stable/c/bd2ddb3fe9052ad8703593bbec26ecc7ca92869e
- https://git.kernel.org/stable/c/d8fdf33d6fcfb90cbec26299baf2352c84b2d768