Out-of-bounds read in Linux kernel - CVE-2026-89621
Published: September 12, 2026
Vulnerability identifier: #VU149183
CSH Severity: Low
CVSS v4: 2.4 [CVSS:4.0/AV:P/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-89621
CWE-ID: CWE-125
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows an attacker with physical access to disclose uninitialized kernel memory.
The vulnerability exists due to an out-of-bounds read in mcp2221_raw_event() in the MCP2221 HID driver when handling a short MCP2221_I2C_GET_DATA HID report. An attacker with physical access can send a crafted HID report with a length value exceeding the received report size to disclose uninitialized kernel memory.
Affected software
Linux kernel
How to mitigate CVE-2026-89621
Install security update from vendor's repository.