CVE-2026-89622: Linux kernel · HID: mcp2221: clear rxbuf after I2C/SMBus transfer completes
Affects Linux kernelSource CVE Database V5
Not known to be exploited · CVSS 7.8 High · fixed in db2333f88729c8aae062cb171ed058725ff5c901 : patch Linux kernel soon.
Data as of 26 Oct 2026, 13:47 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 5% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in db2333f88729c8aae062cb171ed058725ff5c901, d6c6b293173c0ea87189501cbd77e8fa677814a1, bd146a8ff107c6d77e75597decbcd1df0d7900d6 +2
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 11 Sep 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in– |
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.
References
- git.kernel.org/stable/c/bd146a8ff107c6d77e75597decbcd1df0d7900d6 (opens in a new tab)
- git.kernel.org/stable/c/d6c6b293173c0ea87189501cbd77e8fa677814a1 (opens in a new tab)
- git.kernel.org/stable/c/03c34309eb1bce1b3b5f7c4a94b703f419120383 (opens in a new tab)
- git.kernel.org/stable/c/968546b676d992dd1da3e057d40598231f725996 (opens in a new tab)
- git.kernel.org/stable/c/db2333f88729c8aae062cb171ed058725ff5c901 (opens in a new tab)