Denial of Service Vulnerability in RIOT OS for IoT Devices

CVE-2026-107836

What is CVE-2026-107836?

RIOT OS, an open-source operating system for Internet of Things (IoT) devices, has a vulnerability in its nanoCoAP client function, specifically the nanocoap_sock_get_slice(). In versions 2026.07 and earlier, this function improperly validates the server-controlled size and derived offset against the expected block number. A malicious CoAP server can manipulate this validation, leading to a denial of service condition by crashing the client. It risks exposing adjacent memory areas due to improper buffer calculations, which can compromise the stability of IoT applications without a fixed release to remediate the issue.

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