The Zephyr Bluetooth GATT client CCC-write response handler gatt_write_ccc_rsp() in subsys/bluetooth/host/gatt.c invoked the application's params->subscribe() callback after it had already called params->notify(conn, params, NULL, 0).
Per the public GATT API, a notify callback with NULL data is the documented signal that the subscription has terminated and the bt_gatt_subscribe_params struct may be freed or reused by the application; calling subscribe() on the struct afterwards is a use-after-free, including an indirect call through the freed params->subscribe function pointer.
The error branch is remotely (adjacent) reachable: a Zephyr device acting as a GATT client that calls bt_gatt_subscribe() can be driven into this ordering when a connected GATT server peer answers the CCC write with an ATT Error Response (the peer-supplied error code flows through att_error_rsp -> att_handle_rsp into gatt_write_ccc_rsp).
For applications that free or recycle subscription parameters in their notification-termination handler, this results in memory corruption, a crash (denial of service), or potentially attacker-influenced control flow. The fix reorders the handler so the subscribe() callback runs before the terminating notify(NULL) in both the error and unsubscribe paths.
References
| Link | Resource |
|---|---|
| https://github.com/zephyrproject-rtos/zephyr/commit/c7292f20223637232b6f962141725611a38f6a52 | Patch |
| https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-29xh-jm2m-4qvx | Exploit Patch Vendor Advisory |
Configurations
History
No history.
Information
Published : 2026-07-31 15:16
Updated : 2026-09-01 00:16
NVD link : CVE-2026-10685
Mitre link : CVE-2026-10685
CVE.ORG link : CVE-2026-10685
JSON object : View
Products Affected
zephyrproject
- zephyr
CWE
CWE-416
Use After Free