What is CVE-2026-10663?
In Zephyr's experimental USB host stack (CONFIG_USB_HOST_STACK), usbh_device_disconnect() (subsys/usb/host/usbh_device.c) freed the root usb_device slab object without clearing the cached pointer ctx->root. The bus removal handler dev_removed_handler() (subsys/usb/host/usbh_core.c) decides what to tear down solely from ctx->root, checking only that it is non-NULL. Because UHC controller drivers (e.g. uhc_max3421e, uhc_mcux_common) synthesize UHC_EVT_DEV_REMOVED directly from physical bus line state with no debounce or state guard, an attacker with physical USB access (or a rogue device that bounces its connection) can deliver a second device-removed event after a root device disconnect. The handler then re-enters usbh_device_disconnect() with the dangling pointer, locking a mutex inside the freed object (use-after-free), removing the freed node from the device list, and calling k_mem_slab_free() on the already-freed block (double-free). If the slab block has been reissued to a newly attached device in between, this corrupts a live object. Impact is denial of service (crash) and memory corruption; the attack vector is physical/local. The flaw was introduced in v4.4.0 by the connect/disconnect refactor and is fixed by clearing ctx->root in usbh_device_disconnect() before freeing.
The record classifies CVE-2026-10663 under weakness class CWE-416. Its CVSS v3 base vector states that the flaw requires physical access to the device, needs no prior authentication, needs no user interaction, and has high impact on integrity, availability. 1 affected-product entry is recorded, across 1 vendor, listed below. The identifier was first published 85 days ago.
Severity and exploitation probability
- CVSS v3.1 base score
- 6.1 — MEDIUM
CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H - EPSS (FIRST)
- 0.1% probability of exploitation in the next 30 days, higher than 5.4% of all scored CVEs
- CISA KEV
- Not listed in the CISA Known Exploited Vulnerabilities catalog
- Threadlinqs priority
- 3.3/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
- Published
- 2026-07-12, last modified 2026-07-13
Is CVE-2026-10663 being exploited?
It currently carries a trending score of 31 in the Threadlinqs vulnerability feed.
Affected products and versions
- zephyrproject: zephyr
How to fix CVE-2026-10663
No vendor patch reference has been recorded for CVE-2026-10663 in the tracked sources. Follow the references below for a fix, and treat the products listed above as exposed until the vendor states otherwise.
Threat activity tracking CVE-2026-10663
No threat campaign in the Threadlinqs corpus currently references CVE-2026-10663, in its CVE list or as an indicator. The linkage is recomputed from the live corpus on every daily ingest, so this section fills in as soon as a tracked campaign cites the identifier.
Sources
Enriched from CVE.org, NVD, FIRST EPSS. Last verified by Threadlinqs on . This product uses the NVD API but is not endorsed or certified by the NVD.