Secuno
ENNL
Book demo

CVE-2026-25139

Riot-os Riot out-of-bounds read

9.1 CRITICALPublic exploitEPSS 0.56%
  1. Published4 Feb 2026

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.

CVSS 3.1 breakdown

Attack vectorNetwork
Attack complexityLow
Privileges requiredNone
User interactionNone
ScopeUnchanged
ConfidentialityHigh
IntegrityNone
AvailabilityHigh
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H

Affected products

Riot-os Riot≤ 2025.10

Remediation

No fixed version is recorded in the NVD data. Check the vendor advisory for the latest guidance.

References

Related CVEs

Recent high-severity vulnerabilities sharing a weakness type.

CVE-2026-1078378.2
RIOT is an open-source microcontroller operating system designed for Internet of Things…
CVE-2026-78269.1
A heap-based out-of-bounds read in the BufferSerializerIOv2_ReadBuffer function…
CVE-2026-823348.1
IBM Guardium Data Protection 12.0, 12.1, 12.2 is vulnerable to a heap-based…
CVE-2026-144968.2
IBM DataPower Gateway 10.5.0.0 through 10.5.0.22, 10.6.1 through 10.6.6, 10.6.0.0…
CVE-2026-764578.6
As part of Cisco's ongoing commitment to proactive security and product quality, the…
CVE-2026-772148.2
libexpat before commit 13c5f63 contains a heap buffer over-read vulnerability in…

Frequently asked

Is CVE-2026-25139 being actively exploited?

CVE-2026-25139 is not in the CISA KEV catalog. A public exploit reference exists, so treat it as exploitable. Its EPSS exploit probability is 0.56%.

How severe is CVE-2026-25139?

CVE-2026-25139 has a CVSS 3.1 base score of 9.1, rated critical. EPSS estimates a 0.56% probability of exploitation.

Which products are affected by CVE-2026-25139?

Affected products include Riot-os Riot.

How do I fix CVE-2026-25139?

Apply the vendor's patch or advisory guidance, then verify no affected versions remain across your devices.

How Secuno handles this

Secuno correlates vulnerabilities like CVE-2026-25139 against the real software inventory on every managed device, every day. Rather than a static severity, each match is scored in context: exploit availability, EPSS, the asset's exposure, and business criticality decide where it lands in the queue. If an affected version is present anywhere across your portfolio, it surfaces automatically with a prioritised remediation path.

See how prioritisation worksBook a demo

Get Patch this first every Monday

Five vulnerabilities that matter this week, ranked on real exploitation. Plain language, one email, no spam.

You can unsubscribe with one click from every issue. We handle your details as described in our privacy policy.

Data from the NVD, CISA KEV catalog and FIRST EPSS. CVSS 3.1 base score shown where available.