---
id: CVE-2026-10675
title: >-
  Bluetooth Mesh PB-ADV: invalidated provisioning link kept alive indefinitely,
  blocking (re)provisioning (DoS)
summary: >-
  In Zephyr's Bluetooth Mesh PB-ADV provisioning bearer
  (subsys/bluetooth/mesh/pb_adv.c), prov_msg_recv() rescheduled the provisioning
  protocol watchdog timer unconditionally at the top of the function, before the
  FCS check and before the …
severity: medium
cvss: 4.3
cvssVector: 'CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L'
cvssSource: cna
cwe:
  - CWE-400
vendor: zephyrproject
product: zephyr
affected:
  - zephyr >= 3.5.0 < 4.3.1
  - zephyr >= 4.4.0 < 4.4.2
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-07-22T19:32:13.205050Z'
published: '2026-07-21'
updated: '2026-10-15'
sourceUpdated: '2026-10-15T22:10:17.059Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-10675'
references:
  - url: >-
      https://github.com/zephyrproject-rtos/zephyr/commit/3f3c37edf80262b838ef5402fec9880c07892e4e
    label: Fix commit
  - url: >-
      https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-4rwg-6mr4-55hc
    label: GHSA-4rwg-6mr4-55hc
tags:
  - cve.org
epss: 0.00389
epssPercentile: 0.31337
ingestedAt: '2026-10-15T22:48:25.569Z'
---

## Overview

In Zephyr's Bluetooth Mesh PB-ADV provisioning bearer (subsys/bluetooth/mesh/pb_adv.c), prov_msg_recv() rescheduled the provisioning protocol watchdog timer unconditionally at the top of the function, before the FCS check and before the ADV_LINK_INVALID check. Once a provisioning attempt fails, prov_failed() sets ADV_LINK_INVALID and the only recovery path is the protocol timer firing (protocol_timeout -> prov_link_close -> close_link -> reset_adv_link and re-enabling of scanning and the unprovisioned device beacon).

A remote, unauthenticated attacker on the BLE advertising channel can first induce a provisioning failure (e.g. with a malformed generic-provisioning PDU) and then transmit any FCS-valid PB-ADV transaction PDU on the same link ID more often than once per protocol timeout (60 s, or 120 s for OOB input/output). Because each such packet reset the timer even on an invalidated link, protocol_timeout never fired, the dead link was never torn down, and the device remained pinned in an un-provisionable state with its unprovisioned beacon disabled and new Link Open requests rejected.

PB-ADV PDUs are processed without authentication and the FCS is a keyless CRC, so no pairing or prior trust is required and the attacker chooses the link ID itself. The impact is a persistent denial of provisioning/re-provisioning service; there is no memory-safety, confidentiality, or integrity impact.

The vulnerable code shipped in releases through v4.4.1. The fix moves the timer reschedule to after the ADV_LINK_INVALID check (and the FCS check before the reset) so an invalidated link can no longer be kept alive by incoming packets.

## Affected

- `zephyr >= 3.5.0 < 4.3.1`
- `zephyr >= 4.4.0 < 4.4.2`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.