Cyber Resilience

CVE-2026-10656

Memory Safety in Zephyrproject Zephyr 4.2.0 – 4.4.0

Public PoCMemory Safety
Published
05 July 2026
Modified
14 July 2026
Patch / advisory
CVSS Score v3.1 4.6
Click a component to see what it means
Raw vectorCVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS Score 0.0026 17th percentile
Risk Priority 35 floored blend · peak EPSS

Summary

CVE-2026-10656 is a medium-severity NULL Pointer Dereference (CWE-476) vulnerability in Zephyrproject Zephyr. Its CVSS base score is 4.6 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Application or System Exploitation (T1499.004); ranked at the 17th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

The strongest mitigations our analysis identified map to SI-10 (Information Input Validation) and SI-11 (Error Handling) — see the control section below for these in your framework.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

The 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…

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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.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1499.004 Application or System Exploitation Impact
Adversaries may exploit software vulnerabilities that can cause an application or system to crash and deny availability to users.
Why these techniques?

NULL dereference in USB UDC driver enables USB host-triggered crash (physical access), directly matching application/system exploitation for DoS.

Confidence: MEDIUM · MITRE ATT&CK Enterprise v19.0

CVEs Like This One

CVE-2026-10593Same product: Zephyrproject Zephyr
CVE-2026-10648Same product: Zephyrproject Zephyr
CVE-2026-5590Same product: Zephyrproject Zephyr
CVE-2026-13351Same product: Zephyrproject Zephyr
CVE-2026-10637Same product: Zephyrproject Zephyr
CVE-2026-10640Same product: Zephyrproject Zephyr
CVE-2026-10651Same product: Zephyrproject Zephyr
CVE-2026-10668Same product: Zephyrproject Zephyr
CVE-2026-10655Same product: Zephyrproject Zephyr
CVE-2026-10657Same product: Zephyrproject Zephyr

Affected Assets

zephyrproject
zephyr
4.2.0 — 4.4.0

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)
  • SI-10 Information Input Validation
  • SI-11 Error Handling
  • SA-11 Developer Testing and Evaluation
Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)

Validate
Prove the fix (OWASP ASVS)

Mitigating Controls (NIST 800-53 r5) AI

prevent

Directly requires validation of the endpoint buffer returned by udc_buf_get before any dereference in the OUT/IN completion handlers, blocking the NULL case that produces the crash.

prevent

Requires explicit error handling for the empty-FIFO condition (returning UDC_EVT_ERROR/-ENOBUFS) instead of an unchecked net_buf_add(NULL, ...) dereference.

prevent

Developer testing and evaluation would have exercised the race between SETUP-packet drain and stale XFER_DONE events, surfacing the missing NULL checks before the driver shipped.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Secure SDLC practices (static analysis, code review, safe coding standards) directly prevent NULL dereference bugs during development.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

detects

Security testing can detect NULL dereference defects before release.

prevents

Secure SDLC mandates defensive coding practices that can prevent NULL dereferences.

prevents

Application security requirements can specify input validation and pointer-safety rules.

prevents

Secure architecture principles encourage defensive design that avoids unsafe pointer use.

prevents

Secure coding standards directly require NULL-pointer checks and safe dereference patterns.

References