CVE-2026-21382: Qualcomm Cologne Buffer Overflow Flaw

CVE-2026-21382 Overview

A memory corruption vulnerability exists in multiple Qualcomm chipset firmware when handling power management requests with improperly sized input/output buffers. This buffer overflow vulnerability (CWE-120) allows a local attacker with low privileges to potentially achieve arbitrary code execution, escalate privileges, or cause system instability on affected devices.

Critical Impact

A local attacker can exploit improperly sized buffer handling in power management routines to corrupt memory, potentially leading to complete system compromise with high confidentiality, integrity, and availability impact.

Affected Products

• Qualcomm Cologne and Cologne Firmware
• Qualcomm FastConnect 6900 and FastConnect 6900 Firmware
• Qualcomm FastConnect 7800 and FastConnect 7800 Firmware
• Qualcomm QCA0000 and QCA0000 Firmware
• Qualcomm SC8380XP and SC8380XP Firmware
• Qualcomm WCD9378C, WCD9380, WCD9385 Audio Codecs and Firmware
• Qualcomm WSA8840, WSA8845, WSA8845H Smart Amplifiers and Firmware
• Qualcomm X2000077, X2000086, X2000090, X2000092, X2000094 and Firmware
• Qualcomm XG101002, XG101032, XG101039 and Firmware

Discovery Timeline

• April 6, 2026 - CVE-2026-21382 published to NVD
• April 8, 2026 - Last updated in NVD database

Technical Details for CVE-2026-21382

Vulnerability Analysis

This vulnerability is classified as a classic buffer overflow (CWE-120: Buffer Copy without Checking Size of Input). The flaw occurs in the power management subsystem of affected Qualcomm firmware when processing power state transition requests. The vulnerable code fails to properly validate the size of input and output buffers before performing memory copy operations, creating an opportunity for memory corruption.

When a power management request is received, the firmware processes buffer data without adequate bounds checking. If an attacker provides a crafted request with buffer sizes that exceed allocated memory regions, the subsequent copy operations will write beyond the intended boundaries. This can overwrite adjacent memory structures, function pointers, or control flow data.

Exploitation requires local access to the affected device, meaning an attacker must have already established a foothold on the target system. Once exploited, the vulnerability enables full compromise of confidentiality, integrity, and availability due to arbitrary memory write capabilities.

Root Cause

The root cause is insufficient input validation in the power management request handler. The firmware code performs buffer copy operations using caller-supplied size values without verifying that these sizes fall within the bounds of the allocated destination buffers. This classic "copy without size checking" pattern allows attackers to specify oversized buffers that trigger out-of-bounds memory writes during processing.

Attack Vector

The attack requires local access to the device with low-privilege user permissions. An attacker can craft malicious power management requests with improperly sized buffer parameters. When the vulnerable firmware processes these requests, it copies data beyond the allocated buffer boundaries, corrupting adjacent memory. This memory corruption can be leveraged to:

1. Overwrite function pointers to redirect execution flow
2. Corrupt critical data structures used by the power management subsystem
3. Escalate privileges by manipulating security-relevant memory regions
4. Cause denial of service through system crashes or hangs

The vulnerability mechanism involves sending power management IOCTL requests or firmware calls with carefully constructed buffer descriptors. The input buffer size field is set to a value larger than the actual allocated memory, causing the firmware to read or write beyond buffer boundaries during processing. For detailed technical information, refer to the Qualcomm April 2026 Security Bulletin.

Detection Methods for CVE-2026-21382

Indicators of Compromise

• Unexpected system crashes or reboots during power state transitions
• Abnormal power management service behavior or error logs
• Memory access violations or kernel panics related to power subsystem components
• Suspicious processes attempting to interact with power management interfaces

Detection Strategies

• Monitor kernel logs and firmware debug output for buffer overflow indicators or memory corruption signatures
• Implement runtime memory protection mechanisms to detect out-of-bounds access attempts
• Deploy endpoint detection solutions capable of identifying anomalous power management API usage patterns
• Audit local user access to power management system interfaces

Monitoring Recommendations

• Enable verbose logging for power management subsystem operations
• Configure SentinelOne agents to monitor for exploitation attempts targeting driver and firmware interfaces
• Implement system integrity monitoring to detect unauthorized firmware modifications
• Review firmware version inventories to identify vulnerable Qualcomm components

How to Mitigate CVE-2026-21382

Immediate Actions Required

• Identify all devices containing affected Qualcomm chipsets by auditing hardware inventories
• Apply firmware updates from device manufacturers as they become available
• Restrict local access to affected devices to trusted users only
• Enable additional kernel-level memory protection features where supported

Patch Information

Qualcomm has acknowledged this vulnerability in their April 2026 Security Bulletin. Device manufacturers (OEMs) will incorporate these fixes into their own firmware updates. Users should contact their device manufacturers for specific firmware update availability and installation instructions. Monitor the Qualcomm April 2026 Security Bulletin for updated patch information.

Workarounds

• Limit local user account privileges on affected devices to reduce attack surface
• Implement mandatory access control policies (SELinux, AppArmor) to restrict access to power management interfaces
• Where possible, disable or restrict unnecessary power management features until patches are applied
• Deploy network segmentation to limit lateral movement potential if a device is compromised

# Configuration example - Restrict power management interface access (Linux example)
# Add to /etc/udev/rules.d/99-power-mgmt-restrict.rules
SUBSYSTEM=="power_supply", MODE="0640", GROUP="power_admin"

# Verify Qualcomm firmware versions on Android devices
adb shell getprop ro.board.platform
adb shell cat /sys/firmware/devicetree/base/model