CVE-2025-47400: Qualcomm Pandeiro Buffer Overflow Flaw

CVE-2025-47400 Overview

CVE-2025-47400 is a high-severity vulnerability affecting multiple Qualcomm chipsets and firmware components. The flaw involves a cryptographic operation that copies data into a destination buffer without validating the size of that buffer. This category of weakness is tracked as CWE-126: Buffer Over-read and stems from improper bounds checking inside Qualcomm firmware. A local attacker with low privileges can leverage the issue to compromise confidentiality and integrity of affected devices. Qualcomm documented the vulnerability in the Qualcomm Security Bulletin April 2026.

Critical Impact

A local attacker with low privileges can trigger a cryptographic buffer-handling flaw across Qualcomm Snapdragon, WCN, WCD, and WSA firmware, leading to high impact on confidentiality and integrity.

Affected Products

• Qualcomm Snapdragon 8 Elite Gen 5 and associated firmware
• Qualcomm Pandeiro, Themisto, SW6100, and SW6100P platforms and firmware
• Qualcomm WCD9395, WCN7860, WCN7861, WSA8840, WSA8845, and WSA8845H audio/connectivity firmware

Discovery Timeline

• 2026-04-06 - CVE-2025-47400 published to NVD
• 2026-04-08 - Last updated in NVD database

Technical Details for CVE-2025-47400

Vulnerability Analysis

The vulnerability resides in a cryptographic routine within Qualcomm firmware that copies data into a destination buffer without first validating the buffer size. When the source data exceeds the assumed bounds, the routine reads or writes beyond the buffer boundary. This condition matches the pattern described by CWE-126: Buffer Over-read, which is commonly triggered when length fields are trusted without verification.

The affected components span Qualcomm's Snapdragon 8 Elite Gen 5 application processor, the Pandeiro and Themisto platforms, the SW6100 and SW6100P automotive/connectivity chips, the WCD9395 audio codec, the WCN7860 and WCN7861 Wi-Fi/Bluetooth modules, and the WSA8840, WSA8845, and WSA8845H smart speaker amplifiers. Cryptographic code paths shared between these firmware images inherit the same flaw.

Root Cause

The root cause is missing size validation prior to a buffer copy operation in a cryptographic code path. The firmware assumes that the supplied length is within the bounds of the destination buffer and copies data without performing a comparison against the allocated size. Attacker-controlled or malformed inputs reaching this routine cause out-of-bounds memory access.

Attack Vector

The vulnerability requires local access and low privileges, with no user interaction. An attacker executing code on the device can reach the affected cryptographic interface and supply crafted input to the unchecked copy operation. Successful exploitation results in high impact to confidentiality and integrity, exposing or corrupting sensitive cryptographic material processed by the firmware. No public proof-of-concept exploit and no in-the-wild exploitation have been reported.

No verified exploit code is publicly available. Refer to the Qualcomm Security Bulletin April 2026 for vendor-confirmed technical details.

Detection Methods for CVE-2025-47400

Indicators of Compromise

• No vendor-published indicators of compromise are available for CVE-2025-47400 at this time.
• Unexpected firmware crashes, kernel panics, or cryptographic subsystem resets on Qualcomm Snapdragon 8 Elite Gen 5 devices may warrant investigation.

Detection Strategies

• Inventory mobile, automotive, and IoT assets to identify devices built on the affected Qualcomm chipsets and firmware revisions listed in the April 2026 bulletin.
• Correlate firmware build identifiers reported by device management platforms against Qualcomm's patched versions to flag exposed endpoints.
• Monitor for anomalous local process behavior interacting with cryptographic device drivers or trusted execution components.

Monitoring Recommendations

• Ingest mobile device management (MDM) and unified endpoint management telemetry to track patch levels across the Qualcomm-based fleet.
• Watch vendor firmware update channels for OEM-released images that incorporate Qualcomm's April 2026 fixes.
• Alert on repeated cryptographic API failures or driver restarts that could indicate exploitation attempts against the unchecked copy routine.

How to Mitigate CVE-2025-47400

Immediate Actions Required

• Apply the firmware updates referenced in the Qualcomm Security Bulletin April 2026 as soon as OEM builds become available.
• Prioritize patching for devices that handle sensitive cryptographic material, including smartphones with the Snapdragon 8 Elite Gen 5 and connected automotive platforms using SW6100 or SW6100P.
• Restrict installation of untrusted applications on affected devices to reduce the local attack surface until firmware updates are deployed.

Patch Information

Qualcomm has published fixes for the affected chipsets and firmware components in the April 2026 security bulletin. Patches are delivered to downstream original equipment manufacturers (OEMs), who integrate them into device-specific firmware images. Administrators should verify that OEM-distributed updates carry the April 2026 Qualcomm security patch level before considering a device remediated.

Workarounds

• No vendor-supplied workaround is documented; firmware update is the supported remediation path.
• Limit physical and local access to affected devices and enforce least privilege for installed applications until patches are applied.
• Disable or remove third-party applications that are not essential, reducing the chance of malicious local code reaching the vulnerable cryptographic interface.

# Example: query Android security patch level to validate remediation status
adb shell getprop ro.build.version.security_patch
adb shell getprop ro.vendor.build.security_patch