CVE-2026-25266 Overview
CVE-2026-25266 is a memory corruption vulnerability affecting a broad range of Qualcomm firmware components, including connectivity, audio, and Snapdragon platform chipsets. The flaw occurs when the device processes an Input/Output Control (IOCTL) command while it is in a power-save state. An attacker with local, low-privileged access can trigger the condition to corrupt memory in the affected component, leading to potential code execution at firmware privilege.
The vulnerability is tracked under [CWE-749] (Exposed Dangerous Method or Function) and [CWE-787] (Out-of-bounds Write). Qualcomm addressed it in the Qualcomm Security Bulletin May 2026.
Critical Impact
Successful exploitation can result in arbitrary memory writes within Qualcomm firmware, compromising confidentiality, integrity, and availability of the affected device.
Affected Products
- Qualcomm FastConnect 6900 and FastConnect 7800 connectivity firmware
- Qualcomm WCD937xC, WCD9380, WCD9385, WSA883x, WSA884x audio codec firmware
- Qualcomm SC8380XP, Snapdragon AR1 Gen 1, WCN7861, WCN7880, and X2000-series platform firmware
Discovery Timeline
- 2026-05-04 - CVE-2026-25266 published to NVD
- 2026-05-04 - Qualcomm publishes the May 2026 security bulletin with the fix
- 2026-05-06 - Last updated in NVD database
Technical Details for CVE-2026-25266
Vulnerability Analysis
The defect resides in the IOCTL command handler exposed by the affected Qualcomm firmware components. When the device transitions into a power-save state, the handler fails to correctly validate or synchronize state before servicing an incoming IOCTL request. The mismatch between the expected runtime context and the power-save context produces an out-of-bounds memory write inside the firmware's address space.
Because the affected components include Wi-Fi/Bluetooth connectivity (FastConnect, WCN), audio codecs (WCD, WSA), and Snapdragon platform firmware, the attack surface is broad across mobile, automotive, XR (Snapdragon AR1 Gen 1), and compute (SC8380XP) devices. The corruption occurs at firmware privilege, below the operating system kernel, which significantly raises the impact of any successful write primitive.
Root Cause
The root cause is improper handling of an exposed IOCTL interface ([CWE-749]) combined with an out-of-bounds write ([CWE-787]) when device state is power-save. The firmware does not adequately gate the dangerous method against the runtime power state, allowing the handler path to operate on data structures that are partially uninitialized or incorrectly sized.
Attack Vector
Exploitation requires local access with low privileges and no user interaction. An attacker running a malicious application or driver-level component on the host can issue a crafted IOCTL to the Qualcomm device while it is in power-save mode. The scope is unchanged, but the resulting memory corruption can be leveraged for privilege escalation or persistent firmware compromise.
No public proof-of-concept is available, and the vulnerability is not listed in the CISA Known Exploited Vulnerabilities catalog. The EPSS probability is 0.011%, reflecting the absence of observed exploitation activity at the time of publication.
No verified exploit code is available. Refer to the Qualcomm Security Bulletin May 2026 for vendor-supplied technical details.
Detection Methods for CVE-2026-25266
Indicators of Compromise
- Unexpected kernel log entries referencing Qualcomm driver crashes (wlan, audio, wcd, wsa) immediately after device wake from sleep or suspend.
- Repeated IOCTL calls from non-system processes targeting Qualcomm character devices under /dev/.
- Device reboots, firmware reloads, or subsystem restart (SSR) events correlated with low-privileged user activity.
Detection Strategies
- Monitor endpoint telemetry for processes invoking ioctl() against Qualcomm device nodes outside expected vendor services.
- Correlate power-state transitions (suspend/resume) with subsequent firmware fault traces in dmesg or vendor crash dumps.
- Track installation of unsigned or untrusted local applications that interact with audio or Wi-Fi HAL interfaces.
Monitoring Recommendations
- Forward kernel and HAL logs to a centralized logging or SIEM platform for long-term analysis of driver fault patterns.
- Establish baselines for legitimate IOCTL volume per device node and alert on statistical deviations.
- Audit installed applications with CAP_SYS_ADMIN or equivalent local privileges that may issue device IOCTLs.
How to Mitigate CVE-2026-25266
Immediate Actions Required
- Apply the firmware updates referenced in the Qualcomm Security Bulletin May 2026 as soon as the OEM distributes them.
- Inventory affected SKUs by matching device chipsets against the affected products list (FastConnect, WCD, WSA, WCN, SC8380XP, Snapdragon AR1 Gen 1, X2000, XG1010xx).
- Restrict installation of untrusted local applications on impacted devices until patches are deployed.
Patch Information
Qualcomm released fixed firmware versions in coordination with the May 2026 security bulletin. Device manufacturers (OEMs) integrate these fixes into their own firmware and operating system updates. End users should install the latest vendor security update for their device once it becomes available.
Workarounds
- Limit local user privileges and remove unnecessary applications that interact directly with kernel device interfaces.
- Where supported by the OEM, disable or restrict access to vendor IOCTL interfaces that are not required for normal operation.
- Enforce code-signing and application allowlisting policies to reduce the likelihood of a malicious local process reaching the vulnerable handler.
# Example: list processes with open handles to Qualcomm device nodes (Linux/Android)
for dev in /dev/wcd* /dev/wsa* /dev/wlan* /dev/wcn*; do
[ -e "$dev" ] && lsof "$dev" 2>/dev/null
done
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
