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PatchSiren cyber security CVE debrief

CVE-2026-10656 Zephyrproject CVE debrief

The MAX32xxx USB device controller driver in Zephyr versions prior to the patched version, specifically v4.4.0, contains a vulnerability where it dereferences an endpoint buffer without checking for NULL. This oversight leads to a denial-of-service (device crash) when a USB host aborts an in-flight EP0 control transfer with a new SETUP packet. The crash occurs because the driver processes a stale XFER_OUT_DONE event against an empty FIFO, resulting in a near-NULL pointer dereference that faults and crashes the device. Organizations should be aware that the vulnerability can be exploited by a USB host connected to the device, requiring no authentication. The impact is limited to denial of service, and there are no reports of authentication or data integrity compromise.

Vendor
Zephyrproject
Product
Zephyr RTOS
CVSS
MEDIUM 4.6
CISA KEV
Not listed in stored evidence
Original CVE published
2026-07-05
Original CVE updated
2026-07-08
Advisory published
2026-07-05
Advisory updated
2026-07-08

Who should care

Organizations using Zephyr v4.4.0 with MAX32xxx USB device controllers should apply patches to prevent device crashes. Additionally, operators managing these systems, platform administrators, and security teams should be aware of the vulnerability's impact and take necessary precautions. This includes reviewing system inventories, monitoring for suspicious USB activity, and ensuring that affected systems are updated or mitigated.

Technical summary

The MAX32xxx USB device controller driver (drivers/usb/udc/udc_max32.c) dereferenced an endpoint buffer in its OUT and IN transfer-completion handlers without checking it for NULL. A USB host that aborts an in-flight EP0 control transfer with a new SETUP packet can cause a stale XFER_OUT_DONE event to be processed against an empty FIFO, producing a near-NULL pointer dereference that faults and crashes the device. The fix involves adding NULL checks in the transfer-completion handlers to handle such scenarios gracefully.

Defensive priority

High

Recommended defensive actions

  • Apply patches from Zephyr project
  • Inventory and check affected systems
  • Monitor for suspicious USB activity
  • Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up
  • Review the supplied official advisory or CVE record to validate affected scope, severity, and vendor guidance
  • Plan vendor-supported updates or mitigations through normal change control where exposure is confirmed
  • Track exceptions, retest remediated assets, and close the item only after evidence is documented

Evidence notes

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. This information is based on the CVE record and NVD detail. Further verification is recommended to confirm affected scope and vendor guidance, including reviewing system logs for related events and checking for updated patches or advisories from the Zephyr project.

Official resources

AI-assisted PatchSiren debrief based on the supplied source corpus. The CVE record was published on 2026-07-05T23:16:52.730Z and has not been modified since then.