CVE-2026-79379: Bestechnic BES2300 Buffer Overflow Flaw

CVE-2026-79379 Overview

CVE-2026-79379 is a buffer overflow vulnerability in the SBC_DecodeFrames() function of the Bestechnic Co., Ltd BES2300 Bluetooth Audio System-on-Chip (SoC) firmware. The flaw affects firmware version 3.x and earlier and is fixed in version 5.0. Attackers within Bluetooth range can send a crafted Subband Codec (SBC) frame to trigger the overflow. Successful exploitation causes a Denial of Service (DoS) on the affected audio device.

Critical Impact
A remote attacker within Bluetooth radio range can crash BES2300-based audio devices by transmitting a malformed SBC frame, disrupting audio functionality until the device is restarted.

Affected Products

Bestechnic BES2300 Bluetooth Audio SoC firmware v3.x
Bestechnic BES2300 Bluetooth Audio SoC firmware versions earlier than v3.x
Fixed in Bestechnic BES2300 firmware v5.0

Discovery Timeline

2026-09-08 - CVE-2026-79379 published to the National Vulnerability Database (NVD)
2026-09-09 - Last updated in NVD database

Technical Details for CVE-2026-79379

Vulnerability Analysis

The vulnerability resides in the SBC_DecodeFrames() function, which processes incoming Subband Codec audio frames on the BES2300 SoC. The function fails to properly validate the size of incoming frame data before copying it into a fixed-size buffer. When an attacker transmits a crafted SBC frame with unexpected field values, the decoder writes beyond the allocated buffer boundary.

SBC is the mandatory audio codec for the Bluetooth Advanced Audio Distribution Profile (A2DP). Any Bluetooth audio device using the BES2300 chipset processes SBC frames during standard streaming operations. The overflow condition leads to memory corruption within the firmware runtime, resulting in a Denial of Service.

For deeper technical analysis, refer to the Best Technic CVE-2026-79379 Analysis.

Root Cause

The root cause is missing bounds validation on attacker-controlled frame length fields inside SBC_DecodeFrames(). The function assumes incoming SBC frame headers describe legitimate frame sizes and writes decoded output into a stack or heap buffer without enforcing an upper bound.

Attack Vector

An attacker must be within Bluetooth radio range of a vulnerable BES2300 device. After establishing an A2DP audio streaming session, or during service discovery where SBC payloads are processed, the attacker transmits a crafted SBC frame. The malformed frame triggers the overflow inside the decoder and crashes the firmware. No authentication credentials or user interaction beyond a standard Bluetooth pairing are required for exploitation.

No public proof-of-concept code is available for this vulnerability. Refer to the vendor analysis for the frame structure and reproduction details.

Detection Methods for CVE-2026-79379

Indicators of Compromise

Unexpected reboots or firmware crashes on BES2300-based Bluetooth audio devices during active A2DP streaming sessions.
Repeated Bluetooth connection drops correlated with the presence of unknown or unpaired Bluetooth devices in the local radio environment.
Anomalous SBC frame patterns captured via Bluetooth traffic analyzers, particularly frames with malformed length or block fields.

Detection Strategies

Monitor firmware crash logs and watchdog reset events on BES2300 devices for patterns consistent with decoder faults.
Deploy Bluetooth protocol analyzers in sensitive environments to inspect A2DP SBC payload integrity.
Correlate device availability metrics with wireless environment scans to identify potential radio-range attackers.

Monitoring Recommendations

Track firmware versions across the fleet of BES2300-based devices and flag any device running v3.x or earlier.
Log Bluetooth pairing and connection events on managed audio devices to enable post-incident review.
Establish baseline device uptime metrics so unexplained restarts can be flagged for investigation.

How to Mitigate CVE-2026-79379

Immediate Actions Required

Inventory all Bluetooth audio devices to identify products using the Bestechnic BES2300 SoC.
Upgrade affected devices to firmware version 5.0 or later, which contains the vendor fix.
Restrict Bluetooth discoverability and pairing on affected devices used in sensitive locations until firmware is updated.

Patch Information

Bestechnic addressed the vulnerability in BES2300 firmware version 5.0. Device manufacturers that integrate the BES2300 SoC must incorporate the updated firmware into their product update channels. Refer to the BES2300 Security Overview and Best Technic Company Information for downstream vendor coordination.

Workarounds

Disable Bluetooth on affected devices when they are not actively in use to reduce the attack surface.
Operate affected devices only in physically controlled environments where Bluetooth radio range attackers cannot approach.
Unpair unknown devices and remove stored Bluetooth trust relationships that are no longer required.

bash

# Example: audit paired Bluetooth devices on a Linux host to identify BES2300-based peripherals
bluetoothctl devices
bluetoothctl info <MAC_ADDRESS>
# Remove untrusted or unknown devices
bluetoothctl remove <MAC_ADDRESS>