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CVE-2026-10635 zephyrproject CVE debrief

CVE-2026-10635 is a medium-severity vulnerability in the Zephyr kernel, affecting Xtensa targets with CONFIG_USERSPACE and CONFIG_XTENSA_MMU. The vulnerability arises from the page-table code maintaining a global list of active memory domains. When a domain is destroyed, its node is not removed from the list, leading to a dangling pointer. This can cause a NULL pointer dereference or, if the memory has been freed or reused, page-table memory corruption. The vulnerability is reachable only from privileged kernel/supervisor code, not directly from unprivileged user threads or remotely. Affected versions include Zephyr v4.4.0; the issue was fixed on the main branch by adding sys_slist_find_and_remove() in arch_mem_domain_deinit().

Vendor
zephyrproject
Product
zephyr
CVSS
MEDIUM 6.3
CISA KEV
Not listed in stored evidence
Original CVE published
2026-06-16
Original CVE updated
2026-07-14
Advisory published
2026-06-16
Advisory updated
2026-07-14

Who should care

Developers and users of the Zephyr kernel, especially those using Xtensa targets with CONFIG_USERSPACE and CONFIG_XTENSA_MMU, should be aware of this vulnerability. It is recommended to update to a fixed version of Zephyr to mitigate the issue.

Technical summary

The vulnerability is caused by the page-table code (arch/xtensa/core/ptables.c) not removing the domain's node from the global list xtensa_domain_list when a domain is destroyed via k_mem_domain_deinit(). This leads to a dangling pointer that can cause a NULL pointer dereference or page-table memory corruption when traversed by subsequent arch_mem_map()/arch_mem_unmap() operations.

Defensive priority

Medium

Recommended defensive actions

  • Update to a fixed version of Zephyr (main branch) that includes the fix: adding sys_slist_find_and_remove() in arch_mem_domain_deinit().
  • Avoid using vulnerable versions of Zephyr (e.g., v4.4.0) on Xtensa targets with CONFIG_USERSPACE and CONFIG_XTENSA_MMU.

Evidence notes

CVE-2026-10635 has a CVSS score of 6.3 and is classified as MEDIUM severity. The vulnerability was published and modified on 2026-06-16T06:16:57.770Z. References include commits and advisories from the Zephyr project.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-10635 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-10635

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-10635 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-10635

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.