HID: mcp2221: clear rxbuf after I2C/SMBus transfer completes (CVE-2026-89622) | HOL Guard CVE

Unknown severity · Source severity not reportedCVE-2026-89622

HID: mcp2221: clear rxbuf after I2C/SMBus transfer completes

Answer in brief

CVE-2026-89622 records a Unknown severity vulnerability in HID: mcp2221: clear rxbuf after I2C/SMBus transfer completes. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Sep 11, 2026Updated Sep 11, 2026Source checked Sep 11, 2026First seen by HOL Sep 11, 2026Material review Sep 11, 2026

Upstream Advisory

Key facts

Risk: Unknown severitySource severity not reported
Exploitation: Not marked as known exploited
Affected software: 2 mapped packages or products
Fix availability: Available

Why this deserves its current priority

A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
Linux/Linuxgeneric	>=67a95c21463d066060b0f66d65a75d45bb386ffb <03c34309eb1bce1b3b5f7c4a94b703f419120383 \|\| >=67a95c21463d066060b0f66d65a75d45bb386ffb <968546b676d992dd1da3e057d40598231f725996 \|\| >=67a95c21463d066060b0f66d65a75d45bb386ffb <db2333f88729c8aae062cb171ed058725ff5c901	03c34309eb1bce1b3b5f7c4a94b703f419120383, 968546b676d992dd1da3e057d40598231f725996, db2333f88729c8aae062cb171ed058725ff5c901
Linux/Linuxgeneric	5.7	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for Linux/Linux, Linux/Linux.
Review the reported fix. Update Linux/Linux to 03c34309eb1bce1b3b5f7c4a94b703f419120383 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Sep 11, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 11, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Sep 11, 2026

Sources and claim methodology

Upstream source 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.

Quoted source text, attributed separately from HOL analysis.