CVE-2026-5589 Out-of-bounds write caused by an integer underflow in the Bluetooth Mesh subsystem.
An integer underflow in Zephyr's Bluetooth Mesh subsystem allows nearby attackers to cause out-of-bounds writes, potentially leading to code execution or denial of service.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-5589?
CVE-2026-5589 is a medium-severity vulnerability in Zephyrproject Zephyr, published on 4 Jun 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
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.
Weakness: CWE-787
Which versions are affected by CVE-2026-5589?
It affects 1 product.
Products include Zephyrproject Zephyr.
How do I fix CVE-2026-5589?
No fix has been published for CVE-2026-5589 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-5589 being exploited?
There is no known exploitation of CVE-2026-5589 in the wild and no public exploit code.
Other vulnerabilities in Zephyrproject Zephyr
- CVE-2026-5067 Out-of-bounds read/write in HTTP WebSocket upgrade via non-null-terminated Sec-WebSocket-Key
- CVE-2022-3806 Bluetooth HCI Error Handling Double Free
- CVE-2017-14199 Memory corruption in getaddrinfo
- CVE-2018-1000800 Null dereference in n/a
- CVE-2021-3329 DOS: Incorrect handling of the initial HCI ACL_MTU handshake packet leads to crash of bluetooth host layer
Sources
Also known as GHSA-4pm9-4v7f-x6gr.