Is CVE-2026-10635 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-10635 being exploited in the wild.

How severe is CVE-2026-10635?

Medium severity, with a CVSS score of 6.3, published 16 June 2026.

Which products and versions are affected?

Zephyr Project Zephyr OS 4.4.0.

Is there a fix for CVE-2026-10635?

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-2026-10635 attacked?

It is attacked with local access, in an operating system.

Am I affected by CVE-2026-10635?

Check whether you run Zephyr Project Zephyr OS 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.

CVE-2026-10635: Zephyr OS use-after-free in Xtensa MMU page-table management

CVE-2026-10635 · Severity: medium · CVSS 6.3 · Published 2026-06-16

A vulnerability exists in the Zephyr operating system when running on Xtensa processors. The system fails to properly clean up internal memory management records when a memory domain is destroyed, leaving behind 'dangling' references. This can lead to a system crash or, in more complex scenarios, allow memory corruption that could bypass security protections between different applications. Exploiting this requires high-level administrative privileges on the device.

Technologies: Zephyr Project Zephyr OS. Vendors: Zephyr Project.

Quick answers

Is CVE-2026-10635 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-10635 being exploited in the wild.
How severe is CVE-2026-10635?: Medium severity, with a CVSS score of 6.3, published 16 June 2026.
Which products and versions are affected?: Zephyr Project Zephyr OS 4.4.0.
Is there a fix for CVE-2026-10635?: 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-2026-10635 attacked?: It is attacked with local access, in an operating system.
Am I affected by CVE-2026-10635?: Check whether you run Zephyr Project Zephyr OS 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 use-after-free vulnerability exists in arch/xtensa/core/ptables.c when CONFIG_USERSPACE and CONFIG_XTENSA_MMU are enabled. The function arch_mem_domain_deinit() fails to remove the domain's node from the global xtensa_domain_list before the caller-owned k_mem_domain storage is freed or reused. Subsequent memory mapping operations (arch_mem_map/unmap) traverse this stale list, leading to a NULL pointer dereference or a use-after-free where stale page-table pointers are used for writes. This can result in a denial of service or page-table corruption that undermines userspace isolation. The vulnerability is reachable only via privileged kernel code and was introduced in v4.4.0. It is fixed in the main branch and v4.4-branch by adding sys_slist_find_and_remove() to the deinitialization path.

Affected products

Zephyr Project Zephyr OS 4.4.0

Timeline

2026-06-14: other: Embargo date
2026-06-16: disclosed: Advisory published by Zephyr Project

References

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