{"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","slug":"CVE-2026-5589","body":"## Overview\n\nAn 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.\n\n## Affected\n\n- `Zephyr < 4.3.1`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":35,"depthScoreParts":{"impact":34.7,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}