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CVE-2026-10638 zephyrproject CVE debrief

CVE-2026-10638 is a medium-severity denial of service vulnerability in Zephyr's networking stack. The vulnerability exists in the ICMPv6 implementation, specifically in the handling of Echo Request (ping) and error responses. When an ICMPv6 packet is sent, the code attempts to access the network interface from the packet after it has been freed, leading to a use-after-free read and potential write through an attacker-influenceable pointer. This can cause a crash and potentially lead to memory corruption.

Vendor
zephyrproject
Product
zephyr
CVSS
MEDIUM 5.9
CISA KEV
Not listed in stored evidence
Original CVE published
2026-06-16
Original CVE updated
2026-07-17
Advisory published
2026-06-16
Advisory updated
2026-07-17

Who should care

Users of Zephyr networking with CONFIG_NET_NATIVE_IPV6, specifically versions roughly between v4.2.0 and v4.4.0, should be aware of this vulnerability.

Technical summary

The vulnerability is caused by the ICMPv6 implementation's failure to cache the network interface pointer before sending the packet. This leads to a use-after-free read and potential write when trying to update statistics. An unauthenticated remote attacker can trigger this flaw by sending an ICMPv6 Echo Request (ping) or an IPv6 packet that elicits an ICMPv6 error.

Defensive priority

MEDIUM

Recommended defensive actions

  • Update to a version of Zephyr that includes the fix, which caches the interface pointer before sending and uses it for all statistics updates.
  • Avoid sending untrusted ICMPv6 packets to vulnerable systems.

Evidence notes

The vulnerability is documented in the CVE record [cve-org] and the NVD detail page [nvd]. Additional information can be found in the Zephyr project's security advisory [ref-5] and the commit that fixes the issue [ref-4].

Sources and references

Verified primary and authoritative sources

  • CVE-2026-10638 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-10638

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

  • CVE-2026-10638 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-10638

    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.