CVE-2026-21379: Qualcomm Aqt1000 Buffer Overflow Flaw

CVE-2026-21379 Overview

CVE-2026-21379 is a memory corruption vulnerability affecting a broad range of Qualcomm chipsets and firmware components. The flaw occurs when memory is allocated with sizes that exceed the maximum allowed value, leading to memory corruption conditions. Qualcomm disclosed the issue in its July 2026 Security Bulletin, and it is classified under CWE-126: Buffer Over-read.

The vulnerability requires local access and low privileges to exploit, with no user interaction needed. Successful exploitation can compromise confidentiality, integrity, and availability on affected devices, including Snapdragon compute platforms, FastConnect wireless modules, WCD audio codecs, and WSA smart speaker amplifiers.

Critical Impact
A local, low-privileged attacker can trigger memory corruption in Qualcomm firmware components, potentially leading to code execution in a privileged firmware context across dozens of chipset families.

Affected Products

Qualcomm Snapdragon compute platforms (7c+ Gen 3, 8c, 8cx, 8cx Gen 2 5G, 8cx Gen 3)
Qualcomm FastConnect wireless subsystems (6200, 6700, 6800, 6900, 7800)
Qualcomm WCD audio codecs and WSA smart speaker amplifiers (WCD9340–WCD9385, WSA8810–WSA8845H)

Discovery Timeline

2026-07-06 - CVE-2026-21379 published to NVD
2026-07-07 - Last updated in NVD database
July 2026 - Disclosed in the Qualcomm Security Bulletin July 2026

Technical Details for CVE-2026-21379

Vulnerability Analysis

The vulnerability stems from unsafe memory allocation logic within Qualcomm firmware. When a caller requests an allocation with a size that exceeds the maximum permitted value, the allocator fails to correctly reject or bound the request. The resulting condition leads to memory corruption, categorized under CWE-126: Buffer Over-read.

Because the flaw resides in firmware shared across compute platforms, wireless modules, and audio DSP components, the affected surface is unusually wide. A local attacker on the device — for example, a compromised user-space process able to reach a firmware interface — can supply crafted size parameters to trigger the condition. The impact spans confidentiality, integrity, and availability, consistent with corruption of firmware-managed memory structures.

Root Cause

The root cause is missing or improper validation of size parameters passed into the memory allocator. Instead of clamping or rejecting oversized values, the allocator proceeds with an unsafe allocation path. This creates a condition where adjacent memory can be read or overwritten, enabling attacker-controlled data to influence firmware state.

Attack Vector

Exploitation requires local access to the target device and low-level privileges sufficient to reach the vulnerable firmware interface. No user interaction is required. Attackers typically chain such firmware flaws with a user-space foothold (for example, via a compromised application) to escalate into the firmware or kernel trust boundary. Detailed exploitation code is not publicly available and no in-the-wild exploitation has been reported.

The vulnerability manifests in Qualcomm's firmware memory allocation path when size validation fails. See the Qualcomm Security Bulletin July 2026 for vendor-provided technical details.

Detection Methods for CVE-2026-21379

Indicators of Compromise

Unexpected crashes, panics, or reboots involving Qualcomm firmware components such as FastConnect, WCD audio codecs, or Snapdragon compute subsystems.
Kernel or firmware log entries indicating allocation failures, memory corruption, or watchdog resets on affected chipsets.
Anomalous behavior from user-space applications that interact with Qualcomm firmware interfaces immediately before device instability.

Detection Strategies

Inventory endpoints and mobile devices to identify hardware using the affected Qualcomm chipset families and correlate against installed firmware build numbers.
Monitor OEM firmware update channels and confirm devices are receiving the July 2026 Qualcomm patch level or later.
Review endpoint telemetry for local privilege escalation attempts or unusual IOCTL activity targeting Qualcomm driver interfaces.

Monitoring Recommendations

Centralize crash and firmware log collection to detect repeated faults in Qualcomm components that could indicate exploitation attempts.
Alert on newly installed or unsigned applications that interact with low-level driver interfaces on affected devices.
Track patch compliance across the fleet and flag any device that remains below the July 2026 Qualcomm security patch level.

How to Mitigate CVE-2026-21379

Immediate Actions Required

Apply the firmware updates referenced in the July 2026 Qualcomm Security Bulletin as soon as they are made available by the OEM for each affected device.
Restrict local access to affected devices and enforce least-privilege for applications capable of reaching Qualcomm firmware interfaces.
Prioritize patching for high-value devices such as executive laptops using Snapdragon compute platforms and connected collaboration endpoints.

Patch Information

Qualcomm addressed the issue in the July 2026 Qualcomm Security Bulletin. Fixes must be delivered downstream by device OEMs as firmware updates for the affected chipsets. Verify that the deployed firmware corresponds to the July 2026 or later Qualcomm patch level.

Workarounds

Limit installation of untrusted applications on devices using affected Qualcomm hardware to reduce the local attacker surface.
Enforce application allowlisting and mobile device management policies that block sideloaded or unsigned code on affected endpoints.
Disable or restrict unused wireless and audio subsystems where operationally feasible until firmware updates are applied.

bash

# Example: verify Qualcomm firmware/patch level on an Android device via adb
adb shell getprop ro.build.version.security_patch
adb shell getprop ro.vendor.build.security_patch
# Confirm the reported date is 2026-07 or later before considering the device patched