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VulnerabilityPublished Updated

CVE-2026-89622: Linux kernel · HID: mcp2221: clear rxbuf after I2C/SMBus transfer completes

Affects Linux kernelSource CVE Database V5

0

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

CVSS 3.1 base score
7.8High
How severe the flaw is on the 0–10 CVSS scale.
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:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 11 Sep 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq 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

ProductAffectedFixed in
LinuxLinuxAffected
  • ≥ 67a95c21463d066060b0f66d65a75d45bb386ffb, < db2333f88729c8aae062cb171ed058725ff5c901
Fixed in
  • db2333f88729c8aae062cb171ed058725ff5c901
LinuxLinuxAffected
  • ≥ 67a95c21463d066060b0f66d65a75d45bb386ffb, < d6c6b293173c0ea87189501cbd77e8fa677814a1
Fixed in
  • d6c6b293173c0ea87189501cbd77e8fa677814a1
LinuxLinuxAffected
  • ≥ 67a95c21463d066060b0f66d65a75d45bb386ffb, < bd146a8ff107c6d77e75597decbcd1df0d7900d6
Fixed in
  • bd146a8ff107c6d77e75597decbcd1df0d7900d6
LinuxLinuxAffected
  • ≥ 67a95c21463d066060b0f66d65a75d45bb386ffb, < 968546b676d992dd1da3e057d40598231f725996
Fixed in
  • 968546b676d992dd1da3e057d40598231f725996
LinuxLinuxAffected
  • ≥ 67a95c21463d066060b0f66d65a75d45bb386ffb, < 03c34309eb1bce1b3b5f7c4a94b703f419120383
Fixed in
  • 03c34309eb1bce1b3b5f7c4a94b703f419120383
LinuxLinuxAffected
  • =5.7
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

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