CVE-2026-27703 identifies a critical buffer overflow vulnerability in RIOT OS versions 2026.01 and earlier, an open-source microcontroller operating system used in IoT devices. The flaw exists in the CoAP well-known core resource handler, which fails to validate the size of user-provided option data before writing it to a fixed-size buffer. This allows an unauthenticated, remote attacker to corrupt neighboring stack locations, including the return address. With a CVSS score of 9.8 Critical, successful exploitation can lead to denial of service or arbitrary code execution. There is currently no evidence of active exploitation, public exploit code, or significant community discussion regarding this vulnerability.
| Vendor | Product | Version(s) | CPE |
|---|---|---|---|
<= 2026.01CPE matchmatch criteria | cpe:2.3:o:riot-os:riot:*:*:*:*:*:*:*:* |
CVSS version used by this source: 3.1
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
The average CVE in this peer group has 0.0 Twitter, 0.1 Reddit, 0.3 Bluesky, 0.3 Mastodon, and 2.4 GitHub mentions.
No media coverage found for this CVE.
The average CVE in this peer group has 0.3 InfoSec Media, 0.0 Vendor Blog, and 0.0 Security Researcher mentions.
Remediation records are not available for this CVE.