# CVE-2026-17050: Zephyr RTOS USB host stack double-free in configuration descriptor

Source: https://junglewise.ai/threats/cve-2026-17050-the-experimental-usb-host-stack-allocates-a-per-device  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-09-21. Updated: 2026-09-26  
License: CC BY 4.0 with a link back

CVE-2026-17050 · Severity: medium · CVSS 5.7 · Published 2026-09-21

Zephyr's experimental USB host stack contains a memory management flaw where a configuration descriptor buffer can be freed twice when a USB device provides malformed or inconsistent descriptor data during enumeration. An attacker controlling a malicious USB device can trigger this double-free to crash the system with a denial of service on systems with heap hardening enabled, or corrupt heap memory on systems without protections, potentially leading to memory disclosure or code execution.

Technologies: [Zephyr Project Zephyr RTOS](https://junglewise.ai/threats/technologies/zephyr). Vendors: [Zephyr Project](https://junglewise.ai/threats/vendors/zephyr-project).

## Quick answers

**Is CVE-2026-17050 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-17050 being exploited in the wild.

**How severe is CVE-2026-17050?** Medium severity, with a CVSS score of 5.7, published 21 September 2026.

**Which products and versions are affected?** Zephyr Project Zephyr RTOS 4.1.0, 4.2.x, 4.3.x, 4.4.x.

**Is there a fix for CVE-2026-17050?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-17050 attacked?** It is attacked from the adjacent network, in an operating system.

**Am I affected by CVE-2026-17050?** Check whether you run Zephyr Project Zephyr RTOS at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

A per-device configuration descriptor buffer allocated from usb_device_heap is freed multiple times due to a dangling pointer: it is released on three failure paths in usbh_device_set_configuration() but the pointer is not nullified, and then freed again in usbh_device_free() which only checks if the pointer is non-NULL. The double-free is triggered entirely by an attached USB peripheral answering configuration descriptor requests with well-formed headers followed by inconsistent or malformed data. On CONFIG_SYS_HEAP_HARDENING_BASIC (default), this results in a kernel panic; without hardening, heap metadata corruption allows overlapping allocations.

## Affected products

- Zephyr Project Zephyr RTOS 4.1.0, 4.2.x, 4.3.x, 4.4.x

## Timeline

- 2026-09-21: disclosed

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