CVE-2026-49868

What it is

RIOT is an open-source microcontroller operating system designed for Internet of Things devices and other embedded systems. Prior to 2026.07, _parse_reply() in sys/net/application_layer/dhcpv6/client.c omits minimum-length validation before passing IA_PD and IA_NA option bodies to sub-option parsers. A malicious or compromised DHCPv6 server can send a REPLY with an option length smaller than the required structure while MODULE_DHCPV6_CLIENT_IA_PD is enabled, causing _parse_ia_pd_option to read past the option body, size_t underflow, and unbounded out-of-bounds heap reads that can crash the device and may expose or corrupt memory. This issue is fixed in version 2026.07.

At a glance

Exploitability

Can be exploited over the network without logging in. High risk of data exposure, data tampering, service disruption.

Exploit odds

0.4% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2026-06-01 22:03 UTC ReservedThe CVE id was reserved by its CNA
2. 2026-10-16 17:17 UTC PublishedDisclosed publicly on CVE.org and NVD
3. 2026-10-21 03:17 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 0.4% in the next 30 days (EPSS).
• Severity: 9.8 CRITICAL (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2026-10-16 17:17 UTC

Last modified

2026-10-21 03:17 UTC

Exploit probability

0.4% · EPSS, next 30 days

Weakness

CWE-125 · Out-of-bounds read

Record status

Deferred

Attack profile CVSS 3.1 · 9.8

Attack vector

Network

Complexity

Low

Privileges needed

None

User interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2026-49868.md and follow it. Check whether this project is affected by CVE-2026-49868. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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