CVE-2026-42807: BoschSensortec COINES SDK Buffer Overflow

CVE-2026-42807 Overview

CVE-2026-42807 is a heap-based buffer overflow [CWE-122] in the PC bridge protocol decoder of Bosch Sensortec COINES_SDK versions 2.10 through 2.12.2. The bridge decoder trusts an attacker-controlled packet length field and forwards oversized payloads into a fixed-size host response queue. A malicious or compromised Universal Serial Bus (USB) or Bluetooth Low Energy (BLE) peripheral can trigger the overflow by advertising payloads up to approximately 3 KB against a 255-byte queue slot. Successful exploitation causes a denial of service through process crash or may allow arbitrary code execution on the host workstation running the SDK tooling.

Critical Impact
A compromised USB or BLE peripheral can corrupt heap metadata on the host system, enabling process crash or arbitrary code execution against developers and testers using the Bosch Sensortec COINES SDK.

Affected Products

Bosch Sensortec COINES_SDK version 2.10
Bosch Sensortec COINES_SDK versions 2.11.x
Bosch Sensortec COINES_SDK versions through 2.12.2

Discovery Timeline

2026-09-10 - CVE-2026-42807 published to the National Vulnerability Database (NVD)
2026-09-10 - Last updated in NVD database

Technical Details for CVE-2026-42807

Vulnerability Analysis

The flaw lives in bridge_decoder.c, the component responsible for parsing protocol frames returned by attached Bosch Sensortec evaluation boards. When the decoder receives a response packet, it reads a length field supplied by the peripheral and passes that value directly to mqueue_add_data, which enqueues the payload for the host application. The queue is backed by fixed-size slots of 255 bytes.

The decoder never compares the declared length against the destination slot size. A memcpy operation then writes the full attacker-declared payload into the smaller heap allocation. When a peripheral advertises a payload near the ~3 KB upper bound of the transport, the copy overwrites adjacent heap metadata and neighboring allocations.

Exploitation requires physical proximity through USB or BLE and some user interaction, such as connecting the device and launching the SDK-based tool. The consequence is a corrupted host heap that can be steered toward controlled writes and, ultimately, code execution in the context of the developer workstation.

Root Cause

The root cause is missing bounds validation between two trust domains. The PC bridge decoder treats the peripheral as trusted and does not enforce that the parsed length field fits within the response queue slot before invoking memcpy.

Attack Vector

An attacker supplies a malicious USB device, a rogue BLE peripheral, or firmware on a compromised Bosch Sensortec evaluation board. When a developer connects the device and the host SDK issues a request, the peripheral replies with a crafted response containing an oversized length field and payload. The decoder copies the payload into an undersized heap buffer, corrupting adjacent heap chunks in the host process.

See the Bosch Security Advisory BOSCH-SA-223618 for protocol-level technical details.

Detection Methods for CVE-2026-42807

Indicators of Compromise

Unexpected crashes or heap corruption errors in COINES SDK host processes shortly after connecting a USB or BLE sensor device.
BLE or USB protocol captures containing bridge response frames with length fields exceeding 255 bytes.
New or unauthorized Bosch Sensortec evaluation boards or BLE peripherals appearing in developer inventory.

Detection Strategies

Monitor endpoint telemetry on engineering workstations for abnormal termination of coines-linked binaries and follow-on child process creation.
Inspect USB and BLE device enumeration events for peripherals presenting Bosch Sensortec vendor identifiers from untrusted sources.
Hunt for post-crash execution of shells, script interpreters, or living-off-the-land binaries spawned from SDK tool processes.

Monitoring Recommendations

Alert on repeated crashes of COINES SDK host tools tied to a specific USB or BLE device session.
Log and review firmware provenance for evaluation boards used in R&D and manufacturing environments.
Correlate peripheral connection events with heap corruption indicators surfaced by Windows Error Reporting or Linux core dumps.

How to Mitigate CVE-2026-42807

Immediate Actions Required

Inventory workstations running Bosch Sensortec COINES_SDK between versions 2.10 and 2.12.2 and prioritize them for patching.
Restrict use of the SDK to trusted, physically controlled Bosch Sensortec evaluation boards until updates are applied.
Disable BLE-based bridge connectivity where USB-only workflows are acceptable, reducing the wireless attack surface.

Patch Information

Bosch PSIRT tracks remediation guidance in Bosch Security Advisory BOSCH-SA-223618. Upgrade to the fixed COINES SDK release identified in that advisory. Rebuild any internal tools that statically link against the vulnerable decoder.

Workarounds

Operate the SDK only on isolated engineering hosts that do not store sensitive credentials or source code repositories.
Block unapproved USB vendor and product identifiers at the endpoint using device control policies.
Pair BLE evaluation boards only in controlled RF environments and reject unexpected advertisements at the pairing stage.

bash

# Example: enumerate installed COINES SDK versions on Linux hosts
find / -type d -name 'coines*' 2>/dev/null
grep -R "COINES_VERSION" /opt /usr/local 2>/dev/null