Bluetooth GATT Characteristic Access Flaw in Zephyr RTOS

CVE-2026-2411

What is CVE-2026-2411?

A security flaw in Zephyr's Bluetooth implementation allows unauthorized access to GATT characteristic values due to improper permission checks. The system mistakenly evaluates the permissions of the Characteristic Declaration instead of the actual Characteristic Value during notification processes, leading to the potential disclosure of sensitive data over insecure connections. This issue arises when a remote peer writes to the Client Characteristic Configuration descriptor, thereby enabling notification or indication, without enforcing the intended security requirements. A patch has been released that resolves this vulnerability by ensuring correct permission checks for characteristic values.

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