CVE-2026-27703RIOT has an Out-of-Bounds Write in nanoCoAP Handler
Updated under an hour ago ()
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It affects RIOT-OS RIOT and 1 other product. Add what you run to find out whether that includes you.
No exploitation reported and no EPSS estimate yet.
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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.
- CVSS
- 7.5 HIGH (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
- Weakness (CWE)
- CWE-787
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- GitHub_M
- NVD analysis
- Analyzed
- Record last updated
- Mar 12, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
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.