{"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","slug":"CVE-2026-10675","body":"## Overview\n\nIn 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).\n\nA 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.\n\nPB-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.\n\nThe 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.\n\n## Affected\n\n- `zephyr >= 3.5.0 < 4.3.1`\n- `zephyr >= 4.4.0 < 4.4.2`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":24,"depthScoreParts":{"impact":23.7,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}