CVE-2026-25508

/// Technical description

ESF-IDF is the Espressif Internet of Things (IOT) Development Framework. In versions 5.5.2, 5.4.3, 5.3.4, 5.2.6, and 5.1.6, an out-of-bounds read vulnerability was reported in the BLE ATT Prepare Write handling of the BLE provisioning transport (protocomm_ble). The issue can be triggered by a remote BLE client while the device is in provisioning mode. The transport accumulated prepared-write fragments in a fixed-size buffer but incorrectly tracked the cumulative length. By sending repeated prepare write requests with overlapping offsets, a remote client could cause the reported length to exceed the allocated buffer size. This inflated length was then passed to provisioning handlers during execute-write processing, resulting in an out-of-bounds read and potential memory corruption. This issue has been patched in versions 5.5.3, 5.4.4, 5.3.5, 5.2.7, and 5.1.7.

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References