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CVE-2026-10640 zephyrproject CVE debrief

CVE-2026-10640 is a MEDIUM severity vulnerability in Zephyr's IPv6 Neighbor Discovery send paths. The vulnerability is caused by a use-after-free issue when updating per-interface ICMP-sent statistics. This can lead to corrupted statistics, denial of service, or potential limited memory corruption. The vulnerability is reachable by any unauthenticated on-link node simply by sending ICMPv6 Neighbor Solicitations to a Zephyr node with native IPv6 enabled.

Vendor
zephyrproject
Product
zephyr
CVSS
MEDIUM 4.2
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

Users of Zephyr versions from v3.3.0 through v4.4.0 with CONFIG_NET_STATISTICS_PER_INTERFACE enabled should be aware of this vulnerability.

Technical summary

The vulnerability is caused by the net_ipv6_send_na, net_ipv6_send_ns, and net_ipv6_send_rs functions in subsys/net/ip/ipv6_nbr.c updating the per-interface ICMP-sent statistics by calling net_pkt_iface(pkt) after net_send_data(pkt) has already returned successfully. This can lead to a use-after-free issue when the network stack owns and releases the packet's reference.

Defensive priority

MEDIUM

Recommended defensive actions

  • Update to a version of Zephyr that includes the fix, which uses the already-available iface argument instead of touching the sent packet.
  • Disable CONFIG_NET_STATISTICS_PER_INTERFACE if not required.

Evidence notes

The CVE-2026-10640 vulnerability was introduced in Zephyr version v3.3.0 and fixed in a later version. The fix uses the already-available iface argument instead of touching the sent packet.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-10640 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-10640

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

  • CVE-2026-10640 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-10640

    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.