Buffer overflow in Zephyrproject Zephyr
CVE-2026-5589
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.
Vulnerability class: Buffer Overflow
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L.
EPSS exploit prediction
EPSS: 0.003 (17.1th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 17th percentile — 17.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.004 · newest: 0.003 · change: -0.001
Affected products
Weakness classification (CWE)
References
- github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-4pm9-4v7f-x6gr (Exploit, Patch, Vendor Advisory)
Frequently asked questions
- What is CVE-2026-5589?
- CVE-2026-5589 is a medium-severity vulnerability in Zephyrproject Zephyr, classified under Out-of-bounds Write. CVSS score: 6.3/10. Published 2026-06-04.
- How severe is CVE-2026-5589?
- Medium severity. CVSS v3 base score is 6.3 out of 10.