CVE-2025-10456 is a high-severity vulnerability affecting the Zephyr real-time operating system (RTOS), specifically in its Bluetooth Low Energy (BLE) stack implementation. The flaw arises from improper handling of BLE fixed channels such as SMP (Security Manager Protocol) or ATT (Attribute Protocol). According to the Bluetooth specification, fixed channels must not be disconnected by the target device. However, due to an integer overflow or wraparound bug in Zephyr's BLE stack, an attacker can trigger the device to attempt disconnection of these fixed channels. This results in undefined behavior that may manifest as assertion failures, system crashes, or memory corruption, depending on the specific BLE stack implementation and runtime conditions. The vulnerability does not require user interaction or privileges and can be exploited remotely over the BLE interface. The CVSS v3.1 score is 7.1, reflecting a high severity primarily due to the potential for denial of service (availability impact) and integrity issues caused by memory corruption. No known exploits are currently reported in the wild, but the vulnerability affects all versions of Zephyr, indicating a broad attack surface among embedded and IoT devices using this RTOS. The lack of patch links suggests that fixes may still be pending or recently released but not yet widely disseminated.

For European organizations, the impact of CVE-2025-10456 can be significant, especially those deploying IoT devices, embedded systems, or industrial control systems running Zephyr RTOS with BLE capabilities. The vulnerability can lead to device crashes or unstable behavior, causing denial of service in critical systems such as medical devices, smart meters, automotive components, or industrial sensors. Memory corruption could potentially be leveraged for further exploitation, though no such exploits are currently known. Disruption of BLE communications may also affect operational continuity and safety in environments relying on wireless sensor networks. Given the increasing adoption of Zephyr in European smart infrastructure and industrial automation, this vulnerability poses a risk to confidentiality indirectly (via potential memory corruption), integrity (due to corrupted BLE communications), and availability (due to crashes). The remote and unauthenticated nature of the exploit increases risk, as attackers can target devices without physical access or user interaction.

European organizations should prioritize the following mitigation steps: 1) Inventory all devices and systems using Zephyr RTOS with BLE functionality to identify affected assets. 2) Monitor Zephyr project repositories and security advisories closely for official patches addressing CVE-2025-10456 and apply them promptly once available. 3) Until patches are deployed, consider disabling BLE functionality on affected devices where feasible, or restrict BLE communications to trusted environments using network segmentation and BLE access controls. 4) Implement runtime protections such as memory corruption detection and watchdog timers to mitigate crash impacts. 5) Employ BLE traffic monitoring and anomaly detection to identify suspicious attempts to exploit fixed channel disconnection. 6) Collaborate with device manufacturers and vendors to ensure timely firmware updates and security support. 7) For critical infrastructure, establish incident response plans that include procedures for handling BLE-related disruptions. These measures go beyond generic advice by focusing on asset identification, proactive patch management, network-level controls, and operational readiness specific to BLE and Zephyr RTOS environments.