CVE-2026-42806

/// Technical description

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

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References