CVE-2025-47406: Qualcomm Cologne Firmware Info Disclosure

CVE-2025-47406 Overview

CVE-2025-47406 is an information disclosure vulnerability affecting a wide range of Qualcomm firmware components, including Snapdragon compute platforms, FastConnect connectivity chipsets, and audio codec controllers. The flaw exists in an IOCTL (Input/Output Control) handler callback that fails to validate buffer size before processing, allowing a local attacker with low privileges to read out-of-bounds memory contents. Qualcomm disclosed the issue in the Qualcomm Security Bulletin May 2026. The vulnerability is tracked under CWE-126 (Buffer Over-read) and CWE-125 (Out-of-bounds Read).

Critical Impact

A local, authenticated attacker can trigger an out-of-bounds read in a Qualcomm IOCTL handler, leaking sensitive kernel or driver memory contents to user space.

Affected Products

• Qualcomm Snapdragon 8cx Gen 3 and Snapdragon 7c+ Gen 3 Compute platforms
• Qualcomm FastConnect 6700, 6900, and 7800 connectivity chipsets
• Qualcomm WCD937x/WCD938x audio codecs and WSA883x/WSA884x speaker amplifiers

Discovery Timeline

• 2026-05-04 - CVE-2025-47406 published to NVD
• 2026-05-06 - Last updated in NVD database

Technical Details for CVE-2025-47406

Vulnerability Analysis

The vulnerability resides in an IOCTL handler callback within affected Qualcomm firmware drivers. When user space sends an IOCTL request, the handler dispatches the call to a registered callback that copies or reads data using a length value supplied through the request. The callback does not verify that the supplied buffer size falls within the allocated kernel buffer boundaries before performing the read operation.

This missing length check causes the driver to read past the end of the intended buffer. Adjacent memory contents — which may include driver state, kernel pointers, cryptographic material, or data belonging to other processes — are then returned to the caller through the IOCTL response path. The issue maps to CWE-126 (Buffer Over-read) and CWE-125 (Out-of-bounds Read).

Root Cause

The root cause is missing input validation on a size argument passed through the IOCTL boundary. The kernel-mode handler trusts a user-controlled length without comparing it against the actual size of the destination or source buffer. This is a classic trust-boundary violation where data crossing from user space to kernel space is not sanitized before use.

Attack Vector

Exploitation requires local access to an affected device and the ability to open the vulnerable device node. The attacker constructs a malformed IOCTL request specifying an oversized length parameter and submits it to the driver. The handler reads beyond the bounds of the source buffer and returns the over-read contents to the caller. No user interaction is required, and the attack is contained to confidentiality impact — integrity and availability are not affected. Public proof-of-concept code is not available at the time of publication.

Detection Methods for CVE-2025-47406

Indicators of Compromise

• Unusual or repeated IOCTL calls from non-system processes targeting Qualcomm WLAN, audio codec, or compute platform device nodes.
• User-space processes issuing IOCTL requests with abnormally large size or length parameters that do not match documented driver interfaces.
• Unexpected access patterns to /dev/ nodes associated with FastConnect, WCD, or WSA Qualcomm components on Snapdragon-based hosts.

Detection Strategies

• Monitor kernel audit logs (auditd on Linux, ETW on Windows on Snapdragon) for repeated IOCTL invocations from low-privilege users against Qualcomm drivers.
• Use kernel sanitizers such as KASAN in development or QA builds to detect out-of-bounds reads in vendor driver code paths.
• Correlate process telemetry with device-node access events to identify processes that should not be interacting with low-level firmware interfaces.

Monitoring Recommendations

• Establish a baseline of legitimate IOCTL usage per device node and alert on deviations in caller identity, frequency, or argument size.
• Forward kernel and driver logs from Snapdragon-based endpoints into a centralized analytics platform for long-horizon correlation.
• Track firmware version inventory across deployed devices and flag systems running pre-May-2026 Qualcomm firmware builds.

How to Mitigate CVE-2025-47406

Immediate Actions Required

• Apply the Qualcomm May 2026 security patches as soon as they are available from your device OEM or platform vendor.
• Inventory all endpoints, IoT devices, and compute platforms using affected Qualcomm chipsets and prioritize patching for multi-tenant or shared-user systems.
• Restrict local logon and limit which users can load drivers or access privileged device nodes on affected hosts.

Patch Information

Qualcomm has released firmware updates addressing the missing buffer-size validation in the affected IOCTL handler. Refer to the Qualcomm Security Bulletin May 2026 for the full list of fixed components and corresponding firmware versions. OEMs typically integrate these fixes into platform-specific firmware releases, so coordinate with the device manufacturer for delivery timelines.

Workarounds

• Where patching is delayed, reduce the local attack surface by removing unnecessary local accounts and enforcing least-privilege application execution.
• Apply OS-level access controls (SELinux, AppArmor, Windows ACLs) to restrict access to vulnerable Qualcomm device nodes to trusted system services only.
• Disable or unload non-essential Qualcomm driver components on systems where the affected functionality is not required.