Critical 9.8Published Oct 16, 2026

CVE-2026-49868RIOT: DHCPv6 client _parse_reply() missing sub-option length check leads to size_t underflow and unbounded OOB heap read

Updated under an hour ago (Oct 28, 2026, 10:40 AM ET)

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It affects RIOT-OS RIOT. Add what you run to find out whether that includes you.

EPSS puts the chance of exploitation in the next 30 days at 0.37%, higher than 31% of scored CVEs.

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Every CVE for RIOT-OS RIOT

Exploited in the last 30 days

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.

CVSS: 9.8 CRITICAL (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Weakness (CWE): CWE-125, CWE-191
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): 0.37% (percentile 31)
Assigned by: GitHub_M
NVD analysis: Deferred
Record last updated: Oct 20, 2026
First seen by InfoSec Signals: Oct 16, 2026

Affected products

Affected products

RIOT-OS RIOT riot_os:riot (from the name)	before 2026.07	CNA record

References

References

https://github.com/RIOT-OS/RIOT/security/advisories/GHSA-p3fx-9qcg-jmcf	x-refsource-confirm
https://github.com/RIOT-OS/RIOT/pull/22322	x-refsource-misc
https://github.com/RIOT-OS/RIOT/commit/c9830dc5f2a9bf97418de4fc7d7167d00a45df17	x-refsource-misc
https://github.com/RIOT-OS/RIOT/releases/tag/2026.07	x-refsource-misc

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.