{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-27703","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","state":"PUBLISHED","assignerShortName":"GitHub_M","dateReserved":"2026-02-23T17:56:51.202Z","datePublished":"2026-03-11T19:38:02.866Z","dateUpdated":"2026-03-12T19:53:21.857Z"},"containers":{"cna":{"title":"RIOT has an Out-of-Bounds Write in nanoCoAP Handler","problemTypes":[{"descriptions":[{"cweId":"CWE-787","lang":"en","description":"CWE-787: Out-of-bounds Write","type":"CWE"}]}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"NONE","baseScore":7.5,"baseSeverity":"HIGH","confidentialityImpact":"NONE","integrityImpact":"HIGH","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N","version":"3.1"}}],"references":[{"name":"https://github.com/RIOT-OS/RIOT/security/advisories/GHSA-qgj4-9jff-93cj","tags":["x_refsource_CONFIRM"],"url":"https://github.com/RIOT-OS/RIOT/security/advisories/GHSA-qgj4-9jff-93cj"}],"affected":[{"vendor":"RIOT-OS","product":"RIOT","versions":[{"version":"<= 2026.01","status":"affected"}]}],"providerMetadata":{"orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","shortName":"GitHub_M","dateUpdated":"2026-03-11T19:38:02.866Z"},"descriptions":[{"lang":"en","value":"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."}],"source":{"advisory":"GHSA-qgj4-9jff-93cj","discovery":"UNKNOWN"}},"adp":[{"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-03-12T19:53:15.324425Z","id":"CVE-2026-27703","options":[{"Exploitation":"poc"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"title":"CISA ADP Vulnrichment","providerMetadata":{"orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP","dateUpdated":"2026-03-12T19:53:21.857Z"}}]}}