Out-of-bounds write in Linux kernel - CVE-2026-31623
Published: April 25, 2026
Vulnerability identifier: #VU127776
CSH Severity: Medium
CVSS v4.0: 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/E:U/U:Green
CVE-ID: CVE-2026-31623
CWE-ID: CWE-787
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vendor: Linux Foundation
Affected software:
Linux kernel
Linux kernel
Detailed vulnerability description
The vulnerability allows an attacker with physical access to cause a denial of service.
The vulnerability exists due to an out-of-bounds write in rx_complete() in the cdc-phonet driver when processing bulk transfers from a malicious USB device claiming to be a CDC Phonet modem. An attacker with physical access can send an unbounded sequence of full-page bulk transfers to cause a denial of service.
How to mitigate CVE-2026-31623
Install security update from vendor's repository.