Reference page — cumulative record through Wednesday, August 19, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.
zephyrproject zephyr — Heap buffer overflow on WireGuard receive path via unbounded incoming packet length
AV AC PR UI S C I A CVSS EPSS %ile KEV
N H N N U N H H 7.4 .0044 37.0 —
AFFECTED
Product Versions Fixed
zephyr 4.4.0 – —
TIMELINE
Jun 2 Reserved by zephyr
Jul 12 EXPLOIT PUBLISHED — CVE-2026-10665 (zephyrproject zephyr). Public exploit reference added.
Jul 12 Published (CNA: zephyr)
Description
In Zephyr's WireGuard subsystem (subsys/net/lib/wireguard), wg_process_data_message() in wg_crypto.c linearizes an inbound transport-data payload into a fixed pool buffer of CONFIG_WIREGUARD_BUF_LEN bytes before decryption. The call net_buf_linearize(buf->data, data_len, pkt->buffer, ..., data_len) passed the attacker-derived data_len as both the destination capacity and the copy length, defeating the function's internal len = min(len, dst_len) bound. data_len is derived from the received UDP datagram length and is only lower-bounded by wg_ctrl_recv() (no upper bound). When data_len exceeds CONFIG_WIREGUARD_BUF_LEN — e.g. when the buffer length is lowered below the link MTU, on links with MTU above the buffer size, or via reassembled IPv4/IPv6 fragments that exceed it — the underlying memcpy writes past the end of the pool buffer, an out-of-bounds write (CWE-787). The overflow occurs before the Poly1305 authentication check, so it requires only a valid receiver session index rather than a valid authenticator, and is reachable by a malicious or compromised peer (or an on-path attacker driving an established session) over the network, yielding remote memory corruption and at minimum a reliable denial of service. The defect was present in the WireGuard implementation shipped in Zephyr 4.4.0. The fix adds an explicit data_len > CONFIG_WIREGUARD_BUF_LEN rejection and corrects the linearize call to pass net_buf_max_len(buf) as the destination capacity.
Lifecycle
Complete event history — 3 events, chronological
| Date | Event | Detail |
| June 2, 2026 | Reserved | Reserved by zephyr |
| July 12, 2026 | EXPLOIT PUBLISHED | EXPLOIT PUBLISHED — CVE-2026-10665 (zephyrproject zephyr). Public exploit reference added. |
| July 12, 2026 | Published | Published (CNA: zephyr) |
Affected
Affected products and packages — 1 row
| Vendor | Product / Package | Ecosystem | Version introduced | Fixed |
| zephyrproject | zephyr | — | 4.4.0 | — |
About this page
This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2026-10665 from the CVE Program record, NVD enrichment, the CISA KEV catalog, EPSS, and OSV advisories. The box score's numbers (CVSS, EPSS, KEV status) are current as of Wednesday, August 19, 2026 UTC and are re-derived as the archive grows; only dated daily editions are immutable pages of record. The authoritative source for this identifier is cve.org.