CVE-2026-25268: Qualcomm Wsa8835 Buffer Overflow Flaw

CVE-2026-25268 Overview

CVE-2026-25268 is a memory corruption vulnerability affecting a broad range of Qualcomm firmware components, including WLAN chipsets, FastConnect connectivity solutions, Snapdragon mobile platforms, and networking pro platforms. The flaw occurs when processing invalid HT40 channel layouts during dynamic channel switching operations. The vulnerability is classified as a stack-based buffer overflow [CWE-121]. A local attacker with low privileges can trigger the condition to corrupt memory, potentially crossing security boundaries between components.

Critical Impact
Successful exploitation can lead to memory corruption with high impact to confidentiality, integrity, and availability across affected Qualcomm firmware, with the scope extending beyond the vulnerable component.

Affected Products

Qualcomm WLAN and connectivity firmware including FastConnect 6700, 6900, and 7800
Qualcomm Snapdragon mobile platforms including Snapdragon 460 and 662, and 5G Modem-RF systems X62/X65/X72/X75
Qualcomm Networking Pro platforms (400, 600, 610, 800, 810, 1200, 1210, 1610) and IPQ/QCN series WLAN SoCs

Discovery Timeline

2026-07-06 - CVE-2026-25268 published to NVD
2026-07-07 - Last updated in NVD database

Technical Details for CVE-2026-25268

Vulnerability Analysis

The vulnerability resides in the WLAN firmware code path that handles dynamic channel switching, specifically when the firmware parses HT40 (High Throughput 40 MHz) channel layout parameters. HT40 operation combines two adjacent 20 MHz channels into a single 40 MHz channel with a defined primary and secondary. During a channel switch announcement or reconfiguration, the firmware must validate the requested channel layout before applying it to hardware state machines.

When the firmware receives an invalid HT40 layout, the parser fails to enforce boundary constraints on channel indices or secondary-channel offsets before writing to fixed-size stack buffers. This produces a stack-based buffer overflow that corrupts adjacent stack memory. Because the vulnerability crosses a scope boundary, the corruption can influence resources beyond the firmware's own security context, extending impact to the host system.

Root Cause

The root cause is missing or insufficient input validation on HT40 channel descriptor fields consumed during dynamic channel switching. The affected routine writes attacker-influenced data into a fixed-length stack buffer without verifying the length or the semantic validity of the channel layout. This maps to CWE-121: Stack-based Buffer Overflow.

Attack Vector

Exploitation requires local access with low privileges on the affected device and no user interaction. An attacker with the ability to interact with the WLAN driver interface, or to influence channel switching parameters submitted to the firmware, can craft an invalid HT40 layout that triggers the overflow. Because the CVSS scope is changed, successful memory corruption in the firmware can impact components outside the initial trust boundary, including the operating system running on the application processor.

No verified public proof-of-concept code is available for CVE-2026-25268. Refer to the Qualcomm Security Bulletin July 2026 for technical details from the vendor.

Detection Methods for CVE-2026-25268

Indicators of Compromise

Unexpected WLAN driver or firmware crashes, kernel panics, or device reboots correlated with Wi-Fi channel switching events
Anomalous dmesg or vendor firmware log entries referencing HT40, channel switch announcement (CSA), or firmware assertion failures
Presence of unauthorized local processes interacting with WLAN control interfaces (nl80211, wpa_supplicant IPC, vendor HAL sockets)

Detection Strategies

Monitor host telemetry for repeated WLAN subsystem restarts or firmware watchdog resets, which can indicate exploitation attempts against the channel-switching code path
Baseline normal channel switching frequency and alert on abnormal bursts of channel-change requests from userland processes
Correlate local privilege activity with WLAN control-plane operations to identify low-privileged processes issuing unusual wireless configuration commands

Monitoring Recommendations

Ingest kernel and WLAN driver logs into a centralized log pipeline for retention and analysis
Track firmware version and patch level across mobile and networking device fleets to identify unpatched Qualcomm components
Enable device attestation and integrity monitoring where supported to detect post-exploitation state changes

How to Mitigate CVE-2026-25268

Immediate Actions Required

Apply the firmware updates referenced in the Qualcomm Security Bulletin July 2026 as soon as OEM images become available
Inventory all affected Qualcomm-based devices, including FastConnect, Snapdragon, IPQ, QCN, and Networking Pro platforms, and prioritize patching for devices exposed to untrusted local users
Restrict local access on affected devices and audit which processes hold privileges to interact with WLAN control interfaces

Patch Information

Qualcomm has published fixes as part of its July 2026 security bulletin. Device manufacturers integrate these firmware updates into OEM releases for phones, access points, gateways, and IoT devices. Confirm the patched firmware version with the specific OEM for each affected product line before considering remediation complete.

Workarounds

Where patching is not immediately possible, limit installation of untrusted applications on affected mobile devices to reduce local attacker access
On networking equipment, restrict administrative and shell access to trusted operators only, and disable unused WLAN radios where feasible
Enforce least privilege for user accounts and services that can interact with wireless configuration APIs

bash

# Example: verify Qualcomm WLAN firmware version on Linux-based platforms
dmesg | grep -iE "qca|ath1[0-2]k|wlan" | grep -i "firmware"
iw dev
iw phy | grep -iE "HT40|channel"