Buffer overflow in Zephyrproject Zephyr
CVE-2026-5068
A remote, unauthenticated BLE peer can trigger a 2-byte out-of-bounds write in the Bluetooth host during L2CAP LE CoC SDU reassembly. When the application enables segmentation (via chan_ops.alloc_buf) and the chosen RX pool has a user_data_size smaller than 2 bytes, the segmentation counter stored in the net_buf user_data area is written out of bounds in l2cap_chan_le_recv_seg (subsys/bluetooth/host/l2cap.c). The observed effects are an AddressSanitizer abort and, without ASan, heap corruption / fatal error.
Vulnerability class: Buffer Overflow
EPSS: 0.005 (38.2th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 7.6 (High). Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H.
Affected products
- Zephyrproject Zephyr
- Zephyrproject-rtos Zephyr — versions 1.14.0
Weakness classification (CWE)
References
- vulnerabilities@zephyrproject.org (Exploit, Patch, Vendor Advisory)
Frequently asked questions
- What is CVE-2026-5068?
- CVE-2026-5068 is a high-severity vulnerability in Zephyrproject Zephyr, classified under Out-of-bounds Write. CVSS score: 7.6/10. Published 2026-06-09.
- How severe is CVE-2026-5068?
- High severity. CVSS v3 base score is 7.6 out of 10.