CVE-2026-25139: Riot-OS Riot

Critical severity, CVSS 9.1. EPSS: 0.6% chance of exploitation in the next 30 days.

RIOT is an open-source microcontroller operating system, designed to match the requirements of Internet of Things (IoT) devices and other embedded devices. In version 2025.10 and prior, multiple out-of-bounds read allow any unauthenticated user, with ability to send or manipulate input packets, to read adjacent memory locations, or crash a vulnerable device running the 6LoWPAN stack. The received packet is cast into a sixlowpan_sfr_rfrag_t struct and dereferenced without validating the packet is large enough to contain the struct object. At time of publication, no known patch exists.

Affected products

• Riot-OS Riot: up to and including 2025.10

Published 2026-02-04. Last modified 2026-06-17.