PT-2026-66758 · Zephyrproject · Zephyr
CVE-2026-10685
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Published
2026-07-31
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Updated
2026-07-31
CVSS v3.1
7.6
High
| Vector | AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H |
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.
Fix
Use After Free
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Weakness Enumeration
Related Identifiers
Affected Products
Zephyr