CVE-2026-10774
Received Received - Intake

Memory Leak in Zephyr Bluetooth Mesh Subnet Key Management

Publication date: 2026-08-02

Last updated on: 2026-08-02

Assigner: Zephyr Project

Description
Zephyr's Bluetooth Mesh subnet key management leaks one PSA Crypto key slot on every subnet-key teardown. In subsys/bluetooth/mesh/subnet.c, net_keys_create() imports the Private Beacon Key into a PSA key slot under CONFIG_BT_MESH_PRIV_BEACONS (enabled by default), but subnet_keys_destroy() guarded the matching psa_destroy_key() with CONFIG_BT_MESH_V1d1. That Kconfig symbol was removed when explicit Mesh 1.0.1 support was dropped, so the destroy branch became permanently dead code and the import is never balanced by a destroy. The imbalanced teardown is reached every time subnet keys are destroyed: deleting a subnet (Config Server NetKey Delete), completing a Key Refresh Procedure (which retires the old key set), and resetting/re-provisioning the node. The over-the-air triggers are processed only under the node's device key, so they are exercisable by the provisioner or network administrator that owns the node, reachable over the Bluetooth Mesh network. With the default CONFIG_MBEDTLS_PSA_KEY_SLOT_COUNT of 16, repeated add/delete or key-refresh cycles exhaust the shared PSA key-slot pool after roughly a dozen rounds. Once exhausted, bt_mesh_private_beacon_key() and thus subnet creation fail: the node can no longer add subnets or complete key refresh, and other PSA crypto consumers on the device may be starved, until the device is rebooted. The fix aligns the destroy guard with the import guard (CONFIG_BT_MESH_PRIV_BEACONS) so each slot is freed.

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Meta Information

Published
2026-08-02
Last Modified
2026-08-02
Generated
2026-08-02
AI Q&A
2026-08-02
EPSS Evaluated
N/A
NVD
CVE-2026-10774
EUVD
EUVD-2026-52002

Affected Vendors & Products

Showing 1 associated CPE
Vendor Product Version / Range
zephyrproject zephyr *

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Exploitability

CWE
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KEV
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CWE ID Description
CWE-401 The product does not sufficiently track and release allocated memory after it has been used, making the memory unavailable for reallocation and reuse.

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Executive Summary

This vulnerability in Zephyr's Bluetooth Mesh involves improper management of PSA Crypto key slots during subnet key teardown. When a subnet key is destroyed, the cleanup process fails to release a key slot because the required configuration guard was removed. This causes the key slot pool to deplete over time, leading to failures in subnet creation and key refresh operations.

Detection Guidance

This vulnerability is specific to Zephyr's Bluetooth Mesh implementation and involves PSA Crypto key slot exhaustion. Detection requires checking for repeated subnet key operations failing or PSA key slot exhaustion errors in logs. Monitor for errors like 'bt_mesh_private_beacon_key() failed' or 'PSA key slot pool exhausted' during subnet deletion, key refresh, or reprovisioning.

Impact Analysis

The vulnerability can cause your Bluetooth Mesh device to stop functioning properly after repeated subnet operations. Once the key slots are exhausted, the device may fail to add new subnets or complete key refreshes. In severe cases, other cryptographic operations on the device could also be affected until a reboot occurs.

Compliance Impact

This vulnerability does not directly impact compliance with GDPR or HIPAA as it relates to Bluetooth Mesh subnet key management and PSA Crypto key slot exhaustion. However, if the vulnerability causes service disruption or data processing failures due to key exhaustion, it could indirectly affect compliance by impairing device functionality required for data protection measures.

Mitigation Strategies

Apply the official patch from Zephyr that aligns the destroy guard with CONFIG_BT_MESH_PRIV_BEACONS. Temporarily reduce subnet operations or reboot devices periodically to free PSA key slots. Avoid frequent subnet deletions or key refresh cycles until patched.

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