CVE-2026-25139 RIOT Vulnerable to Multiple Out-of-Bounds Read When Processing Received 6LoWPAN SFR Fragments

What is CVE-2026-25139?

CVE-2026-25139 is a high-severity vulnerability in RIOT-OS RIOT, published on 4 Feb 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

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.

Weakness: CWE-125

Which versions are affected by CVE-2026-25139?

It affects 1 product.

Products include Riot-Os Riot.

How do I fix CVE-2026-25139?

No fix has been published for CVE-2026-25139 yet. Limit exposure of the affected software until one is available.

Is CVE-2026-25139 being exploited?

There is no known exploitation of CVE-2026-25139 in the wild and no public exploit code.

Other vulnerabilities in RIOT-OS RIOT

• CVE-2024-32017 Buffer overflows in RIOT Critical 9.8
• CVE-2023-33975 RIOT-OS vulnerable to Out of Bounds Write in _rbuf_add Critical 9.8
• CVE-2023-24819 RIOT-OS vulnerable to Buffer Overflow during IPHC receive Critical 9.8
• CVE-2023-24823 RIOT-OS vulnerable to Packet Type Confusion during IPHC send Critical 9.8
• CVE-2021-27357 Memory corruption in n/a Critical 9.8

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as GHSA-c8fh-23qr-97mc.