# CVE-2026-42804: Memory corruption in BHI360 SensorAPI (C-Library)

> A stack-based buffer overflow in the Bosch BHI360 SensorAPI allows attackers to execute arbitrary code or cause denial of service via crafted debug frames.

- **Severity:** High 7.6 (`CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 10 Sep 2026
- **Updated:** 10 Sep 2026
- **Also known as:** GHSA-6jqh-27cv-xqr6

## What is CVE-2026-42804?

CVE-2026-42804 is a high-severity memory corruption vulnerability in Bosch Sensortec BHI360_SensorAPI (C-Library), published on 10 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

A stack-based buffer overflow vulnerability exists in the Bosch Sensortec BHI360 SensorAPI(C-Library) in versions up to and including commit d6b200416a.

The vulnerability is located within the FIFO parsing and debug logging subsystem inside the function bhi360_parse_debug_message() in bhi360_parse.c (lines 1852-1875). 

The parser trusts the first payload byte of a debug frame as the message length (msg_length) and copies that many bytes into a fixed-size 17-byte stack buffer (debug_msg) via memcpy without performing any bounds checking.

A locally or physically positioned attacker (e.g., via a malicious sensor, counterfeit hardware module, or a Man-in-the-Middle on the communication bus) can exploit this vulnerability by injecting a crafted debug frame with a length byte exceeding 16.

This corrupts adjacent stack data, including the saved return address.

Furthermore, because the overflowed buffer is subsequently passed to a printf-style logging sink, the attacker can supply format string specifiers (e.g., %n) to execute arbitrary code on the host microcontroller/SoC or cause a reliable system crash (Denial of Service).

Weakness: CWE-121 (Stack-based Buffer Overflow)

## Which versions are affected by CVE-2026-42804?


## How do I fix CVE-2026-42804?

No fix has been published for CVE-2026-42804 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-42804 being exploited?

There is no known exploitation of CVE-2026-42804 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-42804 and fix it if it is affected.

What it is: CVE-2026-42804 is a high-severity memory corruption vulnerability in Bosch Sensortec BHI360_SensorAPI (C-Library), published on 10 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-42804 in the wild and no public exploit code.

Affected product: Bosch Sensortec BHI360_SensorAPI (C-Library). No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-42804/ (Markdown: https://insights.sbomify.com/CVE-2026-42804/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-42804
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-42804
- OSV: https://osv.dev/vulnerability/CVE-2026-42804

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-42804/
Summaries are generated and may contain mistakes; the official description above is the record.