Qualcomm Chipset Series: Write-what-where Condition Vulnerability in BootROM (CVE-2026-25262 (CVSS 0.0))

Introduction

A critical hardware vulnerability, CVE-2026-25262, has been disclosed in several Qualcomm MDM and MSM chipset series, along with the SDX50 line. This flaw, categorized as a CWE-123: Write-what-where Condition, resides within the BootROM of these chipsets. Exploiting this vulnerability could enable an attacker with physical access to bypass the secure boot chain.

Bypassing the secure boot chain allows for arbitrary code execution with maximum privileges on the affected system. This creates a serious risk to the integrity and confidentiality of devices relying on these Qualcomm components. Understanding such hardware vulnerabilities is crucial for device manufacturers and end-users.

This write-what-where condition in the BootROM presents a fundamental security challenge. Physical access is a prerequisite for exploitation, but the potential for complete system compromise requires reviewing existing security protocols and supply-chain risk monitoring. PurpleOps provides a complete cyber threat intelligence platform to track deep hardware vulnerabilities and their potential weaponization.

What is CVE-2026-25262 and why is it critical?

CVE-2026-25262 is a Write-what-where Condition vulnerability (CWE-123) present in the BootROM of specific Qualcomm chipset series. This flaw allows an attacker who achieves physical access to the target system to subvert the secure boot process, leading to arbitrary code execution with the highest possible system privileges. The vulnerability is critical because the compromise occurs at the earliest stage of device startup, undermining subsequent security layers.

The CVSS v3.1 base score for CVE-2026-25262 is reported as 0.0 (AV:P/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H). This score can appear counter-intuitive given the high impact (Confidentiality, Integrity, and Availability are all rated "High"). The low base score is primarily due to the "Attack Vector: Physical" (AV:P) and "Attack Complexity: High" (AC:H) metrics. Despite the low numeric score, the vulnerability's impact, once exploited, is severe, granting an attacker complete control over the device. The potential for such deep system compromise on mobile hardware, as seen in other critical issues like a Pixel 9 zero-click kernel exploit, shows how serious boot vulnerabilities are.

A Write-what-where condition is a memory corruption flaw where an attacker can write arbitrary data to an arbitrary memory location. In a BootROM, this capability is dangerous. The BootROM is the first code executed when a device powers on, responsible for initializing hardware and loading the primary bootloader. If this initial stage can be manipulated, the entire chain of trust for the device's secure boot process is compromised, allowing an attacker to inject and execute malicious code before any operating system security features are active. This represents a fundamental bypass of device security, affecting the very root of trust.

Which Qualcomm chipsets are affected by CVE-2026-25262?

The CVE-2026-25262 vulnerability impacts a range of Qualcomm MDM, MSM, and SDX chipset series. These chipsets are widely used in various devices, including IoT, automotive, and mobile communications platforms. All versions of the listed affected products are susceptible to this flaw.

The specific Qualcomm products confirmed to be affected are:

  • Qualcomm MDM9x07 (All versions)
  • Qualcomm MDM9x45 (All versions)
  • Qualcomm MDM9x65 (All versions)
  • Qualcomm MSM8909 (All versions)
  • Qualcomm MSM8916 (All versions)
  • Qualcomm MSM8952 (All versions)
  • Qualcomm SDX50 (All versions)

The widespread adoption of these chipsets across numerous device categories means that the potential attack surface is broad. Organizations involved in manufacturing or deploying systems utilizing these Qualcomm components must assess their exposure. This shows the importance of thorough supply-chain risk monitoring. Vulnerabilities in core components can have cascading effects across entire product lines and industries. Understanding these hardware weaknesses is essential for effective breach detection.

Exploitation and Impact of a BootROM Vulnerability

Exploiting CVE-2026-25262 requires physical access to the target system and involves high attack complexity. This means an attacker would need direct interaction with the device and specialized knowledge or tools to trigger the Write-what-where condition within the BootROM. While physical access inherently limits the scale of an attack compared to remote exploits, the severity of the outcome for an individual device is maximal.

Upon successful exploitation, an attacker can bypass the secure boot chain. The secure boot mechanism is designed to ensure that only trusted software, signed by the manufacturer, can execute during the device's startup process. A bypass at the BootROM level means an attacker can load and execute arbitrary, unsigned code before the operating system even begins to load. This grants maximum privileges, effectively handing over complete control of the device to the attacker. This type of hardware attack, often involving manipulation of trusted execution environments (TEEs), has been a focus of security research, as detailed in discussions around TEE hardware attacks.

The impact of such a compromise is severe:

  • Confidentiality Compromise: An attacker can access all data on the device, including sensitive personal information, cryptographic keys, and proprietary business data.
  • Integrity Compromise: Arbitrary code execution allows an attacker to alter the device's operating system, firmware, or installed applications, potentially injecting persistent malware or backdoors.
  • Availability Compromise: The attacker could render the device inoperable, perform denial-of-service attacks, or use the device as a platform for further malicious activities without the user's knowledge.

This vulnerability aligns with broader concerns regarding hardware zero-day exploits impacting mobile security, similar to prior discussions on Qualcomm threats like CVE-2026-21385. Threat actors with resources and motivation for targeted attacks, such as nation-states or sophisticated criminal groups, may seek to develop and use exploits for such vulnerabilities. Intelligence gathering for advanced persistent threats (APTs) often involves insights from underground forums and dark web monitoring services, which PurpleOps provides to track potential weaponization. The vulnerability was reported in March 2025, suggesting a period where devices were vulnerable before public disclosure.

Mitigation and Patches

CVE-2026-25262 is a hardware vulnerability impacting the BootROM. Traditional software patches may not fully fix the issue without firmware updates or potentially hardware revisions. Qualcomm, the vendor, is typically responsible for developing and distributing firmware updates through device manufacturers. Users should monitor for official updates from their device manufacturers.

Kaspersky ICS CERT, who identified this vulnerability, has provided the following mitigation strategies:

  • Monitor for anomalies in device behavior: This includes unusual heating, unexpected reboots, or abnormal battery drain when the device is not in active use. Such signs could indicate unauthorized code execution or system tampering.
  • Exercise strict physical security control over devices: Since physical access is a prerequisite for exploitation, controlling who can physically interact with affected devices is paramount. This includes:
  • Securing facilities where devices are stored or operated.
  • Implementing strong access control measures for physical hardware.
  • Educating personnel on the risks of unattended devices and unauthorized access.

For industrial control systems (ICS) or critical infrastructure components that might use these Qualcomm chipsets, the implications of physical access are severe. Establishing strong physical security perimeters and monitoring internal networks for any indicators of compromise (IOCs) becomes even more critical. While not a direct patch, limiting the exposure window and increasing the cost for an attacker can significantly reduce risk. Organizations can use ransomware intelligence and breach detection to identify post-exploitation activities, even if the initial compromise occurred via physical means.

Technical Takeaways

  • CVE-2026-25262 is a CWE-123: Write-what-where Condition in Qualcomm BootROM affecting MDM9x07, MDM9x45, MDM9x65, MSM8909, MSM8916, MSM8952, and SDX50 chipsets.
  • Exploitation requires physical access to the target system and involves high attack complexity.
  • Successful exploitation bypasses the secure boot chain, enabling arbitrary code execution with maximum privileges.
  • The CVSS v3.1 score is 0.0 (AV:P/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H), indicating high impact despite the low base score due to physical access and high complexity requirements.
  • Mitigation focuses on strict physical security and monitoring for anomalous device behavior.
  • This vulnerability shows the importance of supply-chain risk monitoring and strong physical security controls for devices incorporating affected Qualcomm chipsets.