CVE-2026-21374: Qualcomm Aqt1000 Buffer Overflow Flaw

CVE-2026-21374 Overview

CVE-2026-21374 is a memory corruption vulnerability affecting a broad range of Qualcomm firmware components. The flaw resides in the handling of auxiliary sensor input/output control commands, where the implementation fails to validate buffer sizes before processing supplied data. A local, low-privileged attacker can supply crafted control commands to trigger memory corruption inside the affected firmware component, leading to compromise of confidentiality, integrity, and availability on the device. The weakness is classified under CWE-126: Buffer Over-read. Qualcomm published the issue in its April 2026 security bulletin alongside fixes for impacted Snapdragon, FastConnect, WCD, WCN, and WSA product families.

Critical Impact

Successful exploitation yields high-impact memory corruption on the underlying firmware, enabling potential local privilege escalation or denial of service across a wide spectrum of Qualcomm-based mobile, compute, and connectivity platforms.

Affected Products

• Qualcomm Snapdragon mobile platforms (Snapdragon 460, Snapdragon 662, Snapdragon AR1 Gen 1, Snapdragon 7c/7c Gen 2/7c+ Gen 3, Snapdragon 8c, Snapdragon 8cx and 8cx Gen 2/Gen 3 compute platforms)
• Qualcomm FastConnect connectivity chipsets (FastConnect 6200, 6700, 6800, 6900, 7800)
• Qualcomm audio, codec, and connectivity firmware (AQT1000, WCD9340/9341/9370/9375/9378C/9380/9385, WCN3950, WCN3988, WSA8810/8815/8830/8832/8835/8840/8845/8845H, QCA0000/6391/6420/6430, QCM5430/6490, SC8380XP, SM6250, Video Collaboration VC3, Cologne, and X2000/XG101 series)

Discovery Timeline

• 2026-04-06 - CVE-2026-21374 published to the National Vulnerability Database
• April 2026 - Qualcomm publishes Qualcomm Security Bulletin April 2026 with patch information
• 2026-04-08 - Last updated in NVD database

Technical Details for CVE-2026-21374

Vulnerability Analysis

The vulnerability stems from missing buffer size validation in the code path that processes auxiliary sensor input/output control (IOCTL) commands. When a user-space caller submits a control command with attacker-controlled length or offset fields, the firmware uses those values to read or copy data without verifying they fall within the bounds of the allocated buffer. This produces a buffer over-read condition consistent with [CWE-126], and depending on the surrounding allocator state, can corrupt adjacent kernel or firmware memory. The vulnerability requires local access and low privileges, with no user interaction, and impacts confidentiality, integrity, and availability of the affected device.

Root Cause

The root cause is improper input validation on length, count, or offset parameters passed through the auxiliary sensor I/O control interface. The handler trusts caller-supplied size metadata when copying data between user space and the kernel-resident firmware driver. Because the sensor IOCTL surface is reachable from unprivileged or low-privileged contexts on Android and Snapdragon compute systems, any process able to open the sensor device node can reach the vulnerable code path.

Attack Vector

Exploitation requires local access. An attacker with the ability to execute code on the device, including from a sandboxed application, can issue malformed IOCTL requests to the auxiliary sensor driver to trigger the out-of-bounds memory access. Successful exploitation can be chained with sandbox escapes to elevate privileges or achieve arbitrary code execution within firmware context. No network reachability and no user interaction are needed.

No public proof-of-concept exploit code has been published for CVE-2026-21374 at the time of writing. Refer to the Qualcomm Security Bulletin April 2026 for vendor-supplied technical details.

Detection Methods for CVE-2026-21374

Indicators of Compromise

• Unexpected crashes, kernel panics, or watchdog resets referencing the auxiliary sensor driver or related IOCTL handlers in device logs.
• Unsigned or unknown applications repeatedly opening sensor device nodes such as /dev/sensor* and issuing malformed ioctl() calls.
• Anomalous SELinux denials or audit records tied to sensor HAL processes attempting unusual memory operations.

Detection Strategies

• Inventory all Qualcomm-based endpoints, mobile devices, and compute platforms against the affected component list and identify firmware build numbers that predate the April 2026 patch baseline.
• Collect and analyze kernel log (dmesg, logcat -b kernel) signals for repeated faults inside sensor IOCTL paths, which can indicate fuzzing or exploitation attempts.
• Monitor mobile threat defense telemetry for installation of applications that request access to low-level sensor interfaces without legitimate business need.

Monitoring Recommendations

• Centralize crash and audit logs from managed mobile and compute fleets into a SIEM or data lake to correlate sensor driver faults across devices.
• Track firmware and security patch level (SPL) compliance reporting from MDM/UEM tooling to confirm devices receive the April 2026 Qualcomm patches once OEMs ship them.
• Alert on devices that remain on pre-patch firmware beyond the organization's remediation SLA.

How to Mitigate CVE-2026-21374

Immediate Actions Required

• Identify affected Qualcomm-based assets using the affected product list and prioritize remediation for devices that process sensitive data.
• Apply the April 2026 Qualcomm security update as soon as the corresponding OEM firmware build is available for each device model.
• Restrict installation of untrusted third-party applications on impacted mobile and compute endpoints through MDM/UEM policy until patches are deployed.

Patch Information

Qualcomm addressed CVE-2026-21374 in its April 2026 security bulletin. OEMs and device integrators must consume the patched firmware and ship updated builds to end users. Refer to the Qualcomm Security Bulletin April 2026 for the authoritative list of fixed components and integration guidance.

Workarounds

• No vendor-supplied workaround is documented; patching to the April 2026 firmware baseline is the required remediation.
• Reduce exposure by limiting which applications can reach sensor device nodes, enforcing application allow-listing, and disabling sideloading on managed devices.
• For high-value devices that cannot be patched immediately, isolate them from untrusted networks and restrict physical access to reduce the local attack surface.