CVE-2025-66646

N/A Unknown
Published: December 17, 2025 Modified: December 18, 2025

Description

RIOT is an open-source microcontroller operating system, designed to match the requirements of Internet of Things (IoT) devices and other embedded devices. A vulnerability was discovered in the IPv6 fragmentation reassembly implementation of RIOT OS v2025.07. When receiving an fragmented IPv6 packet with fragment offset 0 and an empty payload, the payload pointer is set to NULL. However, the implementation still tries to copy the payload into the reassembly buffer, resulting in a NULL pointer dereference which crashes the OS (DoS). To trigger the vulnerability, the `gnrc_ipv6_ext_frag` module must be enabled and the attacker must be able to send arbitrary IPv6 packets to the victim. RIOT OS v2025.10 fixes the issue.

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References to Advisories, Solutions, and Tools

Patch Vendor Advisory Exploit Third Party Advisory
https://github.com/RIOT-OS/RIOT/releases/tag/2025.10
Source: security-advisories@github.com

10 reference(s) from NVD

Quick Stats

CVSS v3 Score
N/A / 10.0
EPSS (Exploit Probability)
0.1%
30th percentile
Exploitation Status
Not in CISA KEV

Weaknesses (CWE)