CVE-2026-25139

CVE-2026-25139 is a critical-severity vulnerability in Riot-os Riot with a CVSS 3.x base score of 9.1. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-125.

Key facts

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.

Frequently asked questions

What is CVE-2026-25139?
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.
How severe is CVE-2026-25139?
CVE-2026-25139 has a CVSS 3.x base score of 9.1, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability high.
Is CVE-2026-25139 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (38th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-25139?
CVE-2026-25139 affects Riot-os Riot. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-25139?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
Does CVE-2026-25139 have an EU (EUVD) identifier?
Yes. CVE-2026-25139 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-5374.
When was CVE-2026-25139 published?
CVE-2026-25139 was published on 2026-02-04 and last updated on 2026-06-17.

References

Affected products (1)

More vulnerabilities in Riot-os Riot

All CVEs affecting Riot-os Riot →

Other CWE-125 (Out-of-bounds Read) vulnerabilities

Browse all CWE-125 (Out-of-bounds Read) vulnerabilities →