CVE-2026-10656
MEDIUM 4.6The MAX32xxx USB device controller driver (drivers/usb/udc/udc_max32.c, compatible adi_max32_usbhs) dereferenced an endpoint buffer in its OUT and IN transfer-completion handlers without checking it for NULL. udc_event_xfer_out_done() called net_buf_add(buf, ep_request->actlen) immediately after buf = udc_buf_get(ep_cfg), where udc_buf_get() returns NULL when the endpoint FIFO is empty. A transfer-completion event is queued from interrupt context and processed asynchronously by the driver thread; between queuing and processing, the endpoint FIFO can be drained by host-controlled control flow — in particular udc_setup_received() drains the EP0 OUT/IN FIFOs whenever a new SETUP packet arrives, and dequeue/disable/purge paths drain it likewise. A USB host that aborts an in-flight EP0 control transfer with a new SETUP packet (legal USB behavior) can therefore cause a stale XFER_OUT_DONE event to be processed against an empty FIFO, producing net_buf_add(NULL, ...), a near-NULL pointer dereference that faults and crashes the device. No authentication is required; the attacker is the USB host the device is connected to (physical bus access). Impact is denial of service (device crash). The defect was introduced when the MAX32 UDC driver was added and shipped in Zephyr v4.4.0. The fix adds NULL-buffer checks that return early with UDC_EVT_ERROR/-ENOBUFS in both the OUT-done and IN-done handlers.
No known exploitation, public exploit, or elevated probability at this time. Track for changes.
Exploitation likelihood
0.2%chance of exploitation in 30 days · 9th percentile
Impact if exploited
4.6CVSS 3.1 · MEDIUM
- ConfidentialityNone
- IntegrityNone
- AvailabilityHigh
What an attacker needs
- ⚠Access: Requires physical access to the device
- ✓Privileges: No account or privileges required
- ✓User interaction: No user interaction needed
- ✓Complexity: No special conditions — reliably repeatable
✓ lowers the bar for an attacker · ⚠ raises it
Proof of concept & exploit code
- reference https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-58p9-6mjq-rf2m
- github-search Search GitHub for public PoC repos
Test against your own equipment
curl -s https://vulnpedia.com/cve/CVE-2026-10656/poc.jsonMachine-readable PoC index for this CVE (for automation).Listed for defensive triage, patch verification, and authorized testing on systems you own. Machine-readable: /cve/CVE-2026-10656/poc.json
Weakness (CWE)
- CWE-476: memory-safety
CVSS vector
CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Known Affected Software Configurations
| Vendor | Product | Version range |
|---|---|---|
| Zephyrproject | Zephyr | ≥ 4.2.0 and ≤ 4.4.0 |
All CVSS metrics
- MEDIUM 4.6 v3.1 · CNA Primary
CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - MEDIUM 4.6 v3.1 · NVD Secondary
CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H