CVE-2026-24081: Bluetooth Channel Map DOS Vulnerability

CVE-2026-24081 Overview

CVE-2026-24081 is a transient denial-of-service (DoS) vulnerability affecting Qualcomm components that handle Bluetooth channel map processing. The flaw triggers when a channel map is received with insufficient used channels while adaptive frequency hopping (AFH) is fully enabled. An adjacent-network attacker within Bluetooth radio range can send a crafted channel map to disrupt availability on the target device.

The vulnerability is categorized under [CWE-126] (Buffer Over-read). It has a scope change and high availability impact, but no impact to confidentiality or integrity.

Critical Impact
An adjacent attacker within radio range can induce a transient denial of service on affected Qualcomm Bluetooth components, disrupting wireless connectivity and dependent services.

Affected Products

Qualcomm components referenced in the September 2026 Qualcomm Security Bulletin
Devices implementing Bluetooth with adaptive frequency hopping on affected Qualcomm firmware
See the Qualcomm Security Bulletin September 2026 for the complete component list

Discovery Timeline

2026-09-17 - CVE-2026-24081 published to the National Vulnerability Database (NVD)
2026-09-17 - Last updated in NVD database

Technical Details for CVE-2026-24081

Vulnerability Analysis

The vulnerability resides in the Bluetooth channel map processing routine within affected Qualcomm firmware. Bluetooth adaptive frequency hopping (AFH) uses a channel map to indicate which of the 79 (Bluetooth Classic) or 37 (Bluetooth Low Energy) physical channels are marked as used or unused. When AFH is fully enabled, the controller depends on the map containing a sufficient number of used channels for hop selection.

When a channel map is processed that specifies insufficient used channels, the firmware performs a buffer over-read while attempting to select the next hop channel. This condition causes the Bluetooth stack to enter a transient failure state, resulting in a denial of service. The scope is changed because the DoS extends beyond the immediate component to affect dependent wireless functionality on the device.

Root Cause

The root cause is insufficient input validation on the channel map field during AFH processing, corresponding to [CWE-126] (Buffer Over-read). The firmware does not verify that the map contains the minimum number of used channels required by the AFH specification before proceeding with channel selection logic. This missing bounds check permits reads past the intended data structure.

Attack Vector

Exploitation requires adjacent-network access, meaning the attacker must be within Bluetooth radio range of the target. No privileges or user interaction are required. The attacker crafts a Bluetooth channel map advertising an insufficient number of used channels and delivers it during a session where AFH is fully enabled. Processing the malformed map triggers the transient DoS condition.

No verified public exploit code is available. Refer to the Qualcomm Security Bulletin September 2026 for vendor technical details.

Detection Methods for CVE-2026-24081

Indicators of Compromise

Unexpected Bluetooth stack resets, controller crashes, or link losses on affected devices
Kernel or HAL logs indicating channel map validation failures or AFH errors
Repeated disconnection events from a specific nearby Bluetooth peer within radio range

Detection Strategies

Monitor host-side Bluetooth subsystem logs for abnormal error counters tied to AFH and channel map processing
Correlate wireless telemetry with proximity data to identify sustained adjacent-network anomalies
Track firmware crash dumps and controller restart events across managed device fleets

Monitoring Recommendations

Ingest mobile and endpoint Bluetooth diagnostic logs into a centralized analytics pipeline
Alert on repeated Bluetooth controller resets clustered in time or location
Baseline normal AFH channel map error rates and flag statistically significant deviations

How to Mitigate CVE-2026-24081

Immediate Actions Required

Inventory devices running affected Qualcomm Bluetooth components using the September 2026 bulletin as reference
Apply vendor firmware updates distributed by device OEMs as soon as they are available
Disable Bluetooth on non-essential devices operating in untrusted environments until patched

Patch Information

Qualcomm has published fixes as part of the Qualcomm Security Bulletin September 2026. Patches propagate to end-user devices through OEM firmware updates and carrier over-the-air (OTA) releases. Verify the security patch level on managed mobile and IoT devices matches or exceeds the September 2026 bulletin.

Workarounds

Restrict Bluetooth pairing and discovery to trusted peers and environments
Limit use of Bluetooth in public spaces where adjacent attackers may be in range
Enforce mobile device management (MDM) policies that disable Bluetooth on high-risk endpoints until firmware updates are applied

bash

# Example: verify Android security patch level against the September 2026 bulletin
adb shell getprop ro.build.version.security_patch
# Expected output should be 2026-09-01 or later once the OEM update is installed