Bluetooth Flaw “WhisperPair” Found in Some Wireless Audio Devices

Cybersecurity researchers from KU Leuven, a Belgian university, have disclosed a Bluetooth vulnerability called WhisperPair, affecting certain audio devices that implement Google Fast Pair technology.

The findings were published as part of a coordinated security disclosure and document weaknesses in how some wireless accessories handle Fast Pair connections. Google has been informed of the findings and has worked with device manufacturers to address affected Fast Pair implementations.

According to the researchers, the vulnerability stems from incomplete or incorrect implementations of the Fast Pair protocol in some Bluetooth accessories. The issue resides in the device firmware, not in smartphones, operating systems, or Bluetooth stacks used by end-user devices.

Not all Fast Pair–enabled devices are affected, and impact varies depending on the manufacturer and model.

In vulnerable devices, an attacker within Bluetooth range may be able to initiate unauthorized interactions with an accessory. The exact impact depends on the specific device and its firmware, and not all scenarios apply universally.

The researchers emphasize that WhisperPair does not compromise user smartphones directly and does not bypass operating system security controls.

The researchers note that updating a phone or operating system, unpairing or factory-resetting the accessory, or disabling Bluetooth or Fast Pair settings on the phone does not resolve the vulnerability, as the issue exists within the accessory itself.

To reduce risk, users should:

• Check product manuals or official specification pages to verify if a Bluetooth audio device supports Google Fast Pair.

• Install manufacturer-provided firmware updates as soon as they are available, typically through the device’s companion application
• Follow any guidance from the device manufacturer regarding affected models and security patches

Until firmware updates are deployed, general caution when using wireless accessories in public environments may reduce exposure, but does not eliminate the underlying issue.

Because mitigation depends on accessory firmware, the availability and timing of fixes varies by manufacturer.

The findings highlight the importance of proper protocol implementation and long-term firmware support across Bluetooth and other wireless device ecosystems.

Additional technical details are available on project’s offiicial research site here.