CVE-2026-27703
RIOT has an Out-of-Bounds Write in nanoCoAP Handler
CVSS Score
7.5
EPSS Score
0.0%
EPSS Percentile
0th
RIOT is an open-source microcontroller operating system, designed to match the requirements of Internet of Things (IoT) devices and other embedded devices. In 2026.01 and earlier, the default handler for the well_known_core resource coap_well_known_core_default_handler writes user-provided option data and other data into a fixed size buffer without validating the buffer is large enough to contain the response. This vulnerability allows an attacker to corrupt neighboring stack location, including security-sensitive addresses like the return address, leading to denial of service or arbitrary code execution.
| CWE | CWE-787 |
| Vendor | riot-os |
| Product | riot |
| Published | Mar 11, 2026 |
| Last Updated | Mar 12, 2026 |
Stay Ahead of the Next One
Get instant alerts for riot-os riot
Be the first to know when new high vulnerabilities affecting riot-os riot are published — delivered to Slack, Telegram or Discord.
Get Free Alerts →
Free · No credit card · 60 sec setup
CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
High
Availability
None
Affected Versions
RIOT-OS / RIOT
<= 2026.01