Vulnerability · Published Mar 11, 2026 · Assigned by GitHub_M
CVE-2026-27703RIOT has an Out-of-Bounds Write in nanoCoAP Handler
High 7.5
In plain English
A high-severity out-of-bounds write in RIOT from RIOT-OS. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 46% of all known vulnerabilities).
Official 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 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.
Affected products (as reported)
Weakness: CWE-787 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
References
- https://github.com/RIOT-OS/RIOT/security/advisories/GHSA-qgj4-9jff-93cj x_refsource_CONFIRM