---
id: CVE-2026-5589
title: >-
  Out-of-bounds write caused by an integer underflow in the Bluetooth Mesh
  subsystem.
summary: >-
  An integer underflow in bt_mesh_sol_recv() in the Bluetooth Mesh solicitation
  handling (subsys/bluetooth/mesh/solicitation.c) leads to an out-of-bounds
  write. When CONFIG_BT_MESH_OD_PRIV_PROXY_SRV is enabled, the function parses
  solicita…
severity: medium
cvss: 6.3
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L'
cvssSource: adp
cwe:
  - CWE-787
vendor: zephyrproject-rtos
product: Zephyr
affected:
  - Zephyr < 4.3.1
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-06-05T18:27:34.569513Z'
published: '2026-06-04'
updated: '2026-10-15'
sourceUpdated: '2026-10-15T22:10:27.343Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-5589'
references:
  - url: >-
      https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-4pm9-4v7f-x6gr
tags:
  - cve.org
epss: 0.00362
epssPercentile: 0.28391
ingestedAt: '2026-10-15T22:48:25.577Z'
---

## Overview

An integer underflow in bt_mesh_sol_recv() in the Bluetooth Mesh solicitation handling (subsys/bluetooth/mesh/solicitation.c) leads to an out-of-bounds write. When CONFIG_BT_MESH_OD_PRIV_PROXY_SRV is enabled, the function parses solicitation PDUs from raw BLE advertising payloads. The AD parsing loop reads an attacker-controlled length byte (reported_len) and computes reported_len - 3 without checking that reported_len >= 3. When reported_len is less than 3, the subtraction is performed in signed int arithmetic and yields a negative value that bypasses the length guard and is then implicitly converted to a very large size_t when passed to net_buf_simple_pull_mem(). In builds without assertions, this wraps the buffer length and advances the data pointer far out of bounds, so subsequent reads dereference invalid memory. A nearby BLE device can trigger this with a non-connectable advertisement carrying a UUID16 AD structure and a crafted length byte, with no pairing or prior association required, potentially leading to denial of service or arbitrary code execution.

## Affected

- `Zephyr < 4.3.1`

## Remediation

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