HID: mcp2221: clear rxbuf after I2C/SMBus transfer completes
CVE-2026-89622 · published 11 Sept 2026
How serious is it
- Severity: high, CVSS score 7.8 out of 10.
- No exploit prediction (EPSS) score yet.
- Not on the CISA list of exploited vulnerabilities.
- No public exploit in Exploit-DB.
Is your app affected by CVE-2026-89622?
Paste this prompt into Claude Code, Cursor or any AI coding tool: it runs a free Shippable scan of your project and fixes what it finds. Built with Lovable, Bolt or v0? Scan your live app. Or upload your package file.
Who is affected
- Linux Linux: 67a95c21463d066060b0f66d65a75d45bb386ffb to < bd146a8ff107c6d77e75597decbcd1df0d7900d6, 67a95c21463d066060b0f66d65a75d45bb386ffb to < d6c6b293173c0ea87189501cbd77e8fa677814a1, 67a95c21463d066060b0f66d65a75d45bb386ffb to < 03c34309eb1bce1b3b5f7c4a94b703f419120383, 67a95c21463d066060b0f66d65a75d45bb386ffb to < 968546b676d992dd1da3e057d40598231f725996
- Linux Linux: 5.7
How to check
- Find out whether you run the affected product and which version, then compare it with the versions above.
How to fix
Copies a prompt for Claude Code, Cursor or Codex that asks it to check whether you run this product.
- Apply the vendor's update or mitigation from the references below. If there is none yet, limit exposure of the affected service until there is.
- If a vulnerable version was live, check your logs and rotate the secrets that server could read.
The advisory
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.
Check your whole app
Dependencies are only half of it. Free and read-only: before you push, run npx shippable-dev scan localhost:3000 in your project folder, no account needed. For your live app, you prove it's yours with a one-line tag first.
References
- git.kernel.org/stable/c/bd146a8ff107c6d77e75597decbcd1df0d7900d6
- git.kernel.org/stable/c/d6c6b293173c0ea87189501cbd77e8fa677814a1
- git.kernel.org/stable/c/03c34309eb1bce1b3b5f7c4a94b703f419120383
- git.kernel.org/stable/c/968546b676d992dd1da3e057d40598231f725996
- git.kernel.org/stable/c/db2333f88729c8aae062cb171ed058725ff5c901
Merged from CVE List. Last updated 26 Oct 2026. All vulnerabilities · RSS · JSON