---
id: CVE-2026-42806
title: "An out-of-bounds read vulnerability was discovered in the Bosch BME690 SensorAPI (C-driver) in version v1.0.3 and prior, specifically within the field data parsing logic in read_all_field_data (bme69x.c).\r\n\r\nThe driver prefetches heater …"
summary: "An out-of-bounds read vulnerability was discovered in the Bosch BME690 SensorAPI (C-driver) in version v1.0.3 and prior, specifically within the field data parsing logic in read_all_field_data (bme69x.c).\r\n\r\nThe driver prefetches heater …"
severity: medium
cvss: 4.3
cvssVector: 'CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L'
cwe:
  - CWE-125
vendor: Bosch Sensortec
product: BME690 SensorAPI (C)
affected:
  - bme690_sensorapi_c >= 1.0.1 <= 1.0.3
published: '2026-09-10'
updated: '2026-09-10'
sourceUpdated: '2026-09-10T16:17:12.270'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-42806'
references:
  - url: 'https://psirt.bosch.com/security-advisories/BOSCH-SA-223618.html'
    label: psirt@bosch.com
tags:
  - nvd
  - cve.org
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-09-10T15:00:33.822497Z'
ingestedAt: '2026-09-10T09:45:12.028Z'
epss: 0.00205
epssPercentile: 0.09334
---

## Overview

An out-of-bounds read vulnerability was discovered in the Bosch BME690 SensorAPI (C-driver) in version v1.0.3 and prior, specifically within the field data parsing logic in read_all_field_data (bme69x.c).

The driver prefetches heater configuration registers into a contiguous 30-byte stack buffer (set_val) mapping IDAC, RES_HEAT, and GAS_WAIT tables.

When parsing sensor field data, the gas_index is extracted using a 4-bit mask (0..15) but lacks boundary verification against the valid range (0..9).

An attacker or a compromised peripheral mimicking a sensor on the I2C/SPI bus could return a payload with a gas index value of 10 or higher.

This causes the driver to perform an out-of-bounds array access (set_val[20 + gas_index]), reading up to 6 bytes past the stack buffer.

The leaked out-of-bounds byte is then written into the public gas_wait field, which may lead to measurement corruption or leak adjacent stack memory when telemetered or logged.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.