CVE-2025-47374: Qualcomm Fastconnect 6900 Use-After-Free

CVE-2025-47374 Overview

CVE-2025-47374 is a use-after-free vulnerability [CWE-416] affecting a wide range of Qualcomm firmware components. The flaw stems from a race condition between concurrent fence deregistration and signal handling, where one execution path frees a synchronization object while another path continues to dereference it. Successful exploitation can lead to memory corruption in firmware running on Snapdragon-based wireless, audio, and XR platforms. Qualcomm addressed the issue in its Qualcomm Security Bulletin April 2026.

Critical Impact

A local attacker with low privileges can trigger memory corruption in Qualcomm firmware, leading to integrity loss, availability impact, and potential code execution within the affected firmware component.

Affected Products

• Qualcomm FastConnect 6900 and FastConnect 7800 firmware
• Qualcomm Snapdragon AR1 Gen 1 and AR1+ Gen 1 Platform firmware
• Qualcomm SAR1165P, SAR2130P, SXR2230P, SXR2250P, SXR2330P, SXR2350P, WCD9380/9385, WCN7860/7861, WSA8830/8832/8835, XRV7209/9209, and QXM/QLN/QPA series firmware

Discovery Timeline

• 2026-04-06 - CVE-2025-47374 published to NVD
• 2026-04-08 - Last updated in NVD database

Technical Details for CVE-2025-47374

Vulnerability Analysis

The vulnerability is a use-after-free condition triggered by a race between two concurrent firmware code paths. One path performs deregistration of a fence object, a synchronization primitive used to coordinate completion of asynchronous operations. The second path handles signaling of the same fence object. When the deregistration path releases the underlying memory before the signal handler completes its access, the signaling code dereferences a freed object.

The resulting memory access reads or writes to memory that may have been reallocated for unrelated data. Attackers who can influence the timing and content of subsequent allocations can corrupt firmware data structures. Because the issue resides in low-level firmware on wireless, audio, and XR system-on-chip components, successful exploitation can disrupt device operation or alter firmware state.

Root Cause

The root cause is the absence of proper synchronization between the fence deregistration routine and the fence signal handler. Reference counting or locking that should prevent the object from being released while another execution context still holds a pointer is either missing or incorrectly applied. This is a classic [CWE-416] use-after-free pattern compounded by concurrency.

Attack Vector

Exploitation requires local access and low privileges on the host system that interacts with the affected Qualcomm component. The attack complexity is high because the attacker must reliably win a race window between the deregistration and signaling code paths. No user interaction is required. The vulnerability mechanism is described in the Qualcomm Security Bulletin April 2026; no public proof-of-concept code is available.

Detection Methods for CVE-2025-47374

Indicators of Compromise

• Unexpected firmware crashes, watchdog resets, or kernel panics on devices using affected Qualcomm chipsets
• Abnormal wireless, audio, or XR subsystem instability following workload that exercises fence-based synchronization
• Driver or hardware abstraction layer error logs referencing fence deregistration or signal handling failures

Detection Strategies

• Inventory endpoints and IoT devices for affected Qualcomm chipsets using the CPE list from NVD and vendor documentation
• Monitor host operating system logs for repeated subsystem resets that correlate with the affected firmware components
• Correlate process activity invoking graphics, wireless, or audio APIs with firmware fault telemetry to identify exploitation attempts

Monitoring Recommendations

• Enable verbose driver logging for affected Qualcomm subsystems during patch rollout to surface anomalous fence-related faults
• Track firmware version inventory across managed devices to confirm remediation status
• Alert on local privilege escalation chains where unprivileged processes interact heavily with kernel drivers backed by Qualcomm firmware

How to Mitigate CVE-2025-47374

Immediate Actions Required

• Apply firmware updates from device OEMs that incorporate the April 2026 Qualcomm security patches
• Identify all affected chipsets in the environment, including embedded XR headsets, smartphones, and IoT modules using FastConnect, WCN, WSA, and Snapdragon AR platforms
• Restrict local access to affected devices and enforce least-privilege policies on processes that interact with Qualcomm drivers

Patch Information

Qualcomm released fixes for the affected firmware components in the Qualcomm Security Bulletin April 2026. Device manufacturers must integrate the patched firmware into their respective OS and platform updates. Administrators should track OEM advisories for Snapdragon-based products to confirm that downstream patches are available and applied.

Workarounds

• No vendor-provided workarounds are listed; remediation requires the firmware update
• Limit physical and local logical access to affected devices until firmware patches are deployed
• Disable or restrict non-essential applications that interact with vulnerable wireless, audio, or XR subsystems on unpatched devices

# Example: enumerate firmware versions on Android-based devices to verify patch level
adb shell getprop ro.build.version.security_patch
adb shell cat /proc/cmdline | tr ' ' '\n' | grep -i fw