High severity · published Sep 11, 2026
CVE-2026-89622
HID: mcp2221: clear rxbuf after I2C/SMBus transfer completes
7.8
CVSS
0.2%
EPSS
No
On KEV
Description
In the Linux kernel, the following vulnerability has been resolved: HID: mcp2221: clear rxbuf after I2C/SMBus transfer completes mcp_i2c_smbus_read() stores the caller-supplied buffer pointer in mcp->rxbuf for the duration of a transfer but never clears it when the transfer finishes or times out. Once the caller frees or reuses the buffer, mcp->rxbuf becomes a dangling pointer. A delayed or spurious MCP2221_I2C_GET_DATA report can then drive mcp2221_raw_event() to memcpy device data into the freed memory, causing a write use-after-free. Route all return paths through a single exit point that clears mcp->rxbuf and mcp->rxbuf_size, so that the existing !mcp->rxbuf guard in the raw_event handler can reject any report arriving after the transfer has ended.
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Attack vector
Local
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.2% · higher than 6% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
LI
Linux · Linux
67a95c21463d066060b0f66d65a75d45bb386ffb before bd146a8ff107c6d77e75597decbcd1df0d7900d6; 67a95c21463d066060b0f66d65a75d45bb386ffb before d6c6b293173c0ea87189501cbd77e8fa677814a1; 67a95c21463d066060b0f66d65a75d45bb386ffb before 03c34309eb1bce1b3b5f7c4a94b703f419120383; 67a95c21463d066060b0f66d65a75d45bb386ffb before 968546b676d992dd1da3e057d40598231f725996; 67a95c21463d066060b0f66d65a75d45bb386ffb before db2333f88729c8aae062cb171ed058725ff5c901; 5.7 · source: vendor