CVE-2026-10648 — Security Box Score

CVE · referencelatest edition

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.

CVE-2026-10648MEDIUM

zephyrproject zephyr — NULL-pointer dereference in MCUmgr serial/console SMP transport on buffer-pool exhaustion

  AV  AC  PR  UI  S  C  I  A   CVSS    EPSS   %ile   KEV
   L   L   L   N  U  N  N  H    5.5   .0015    4.6     —

AFFECTED
  Product  Versions  Fixed
  zephyr   4.4.0 –   —

TIMELINE
  Jun 2   Reserved by zephyr
  Jun 29  EXPLOIT PUBLISHED — CVE-2026-10648 (zephyrproject zephyr). Public exploit reference added.
  Jun 29  Published (CNA: zephyr)

CWE-476 · CNA: zephyr · CVSS v3.1 · 2 references · NVD status: Modified

Description

mcumgr_serial_process_frag() in subsys/mgmt/mcumgr/transport/src/serial_util.c calls net_buf_reset() on the result of smp_packet_alloc() before checking it for NULL. smp_packet_alloc() uses net_buf_alloc(K_NO_WAIT) against the shared MCUmgr packet pool (CONFIG_MCUMGR_TRANSPORT_NETBUF_COUNT, default 4), which returns NULL when the pool is exhausted. In default builds the __ASSERT_NO_MSG in net_buf_reset is a no-op, so net_buf_simple_reset writes through the NULL pointer (buf->len = 0; buf->data = buf->__buf), causing a fault/crash. The fragment data reaches this code from attacker-controlled bytes on the MCUmgr serial/UART/shell-console transports (smp_uart.c, smp_raw_uart.c, smp_shell.c), and a fresh buffer is allocated at the start of essentially every new packet. An attacker on the serial/console link can flood the transport to drive the 4-entry buffer pool to exhaustion and induce the NULL dereference, crashing the device (denial of service). The defect was introduced after the original MCUmgr rework and shipped in Zephyr v4.4.0. The fix moves the NULL check ahead of net_buf_reset.

Lifecycle

Complete event history — 3 events, chronological
Date	Event	Detail
June 2, 2026	Reserved	Reserved by zephyr
June 29, 2026	EXPLOIT PUBLISHED	EXPLOIT PUBLISHED — CVE-2026-10648 (zephyrproject zephyr). Public exploit reference added.
June 29, 2026	Published	Published (CNA: zephyr)

Affected

Affected products and packages — 1 row
Vendor	Product / Package	Ecosystem	Version introduced	Fixed
zephyrproject	zephyr	—	4.4.0	—

Weaknesses

CWE-476

References (2)

https://github.com/zephyrproject-rtos/zephyr/commit/6f363ec6f7fd6ae9ed7ca2ae66fd9c82dce31c59 [Patch]
https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-j64f-h3ww-f32c [Exploit, Patch, Vendor Advisory]

Authoritative record: CVE-2026-10648 at cve.org

Vendors: zephyrproject

Weaknesses: CWE-476

About this page

This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2026-10648 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.