{"id":"CVE-2026-49868","state":"PUBLISHED","title":"RIOT: DHCPv6 client _parse_reply() missing sub-option length check leads to size_t underflow and unbounded OOB heap read","description":"RIOT is an open-source microcontroller operating system designed for Internet of Things devices and other embedded systems. Prior to 2026.07, _parse_reply() in sys/net/application_layer/dhcpv6/client.c omits minimum-length validation before passing IA_PD and IA_NA option bodies to sub-option parsers. A malicious or compromised DHCPv6 server can send a REPLY with an option length smaller than the required structure while MODULE_DHCPV6_CLIENT_IA_PD is enabled, causing _parse_ia_pd_option to read past the option body, size_t underflow, and unbounded out-of-bounds heap reads that can crash the device and may expose or corrupt memory. This issue is fixed in version 2026.07.","publishedAt":"2026-10-16T16:50:58.750Z","updatedAt":"2026-10-21T02:29:33.220Z","severity":{"score":9.8,"label":"Critical","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","source":"GitHub_M"},"assigner":"GitHub_M","products":["RIOT-OS RIOT"],"affected":[{"vendor":"RIOT-OS","product":"RIOT","versions":[{"version":"< 2026.07","status":"affected"}]}],"references":["https://github.com/RIOT-OS/RIOT/security/advisories/GHSA-p3fx-9qcg-jmcf","https://github.com/RIOT-OS/RIOT/pull/22322","https://github.com/RIOT-OS/RIOT/commit/c9830dc5f2a9bf97418de4fc7d7167d00a45df17","https://github.com/RIOT-OS/RIOT/releases/tag/2026.07"],"weaknesses":["CWE-125","CWE-191"],"ingestedAt":"2026-10-29T20:12:07.131Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/49xxx/CVE-2026-49868.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-49868","state":"PUBLISHED","datePublished":"2026-10-16T16:50:58.750Z","dateUpdated":"2026-10-21T02:29:33.220Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-06-01T22:03:19.641Z"},"containers":{"cna":{"title":"RIOT: DHCPv6 client _parse_reply() missing sub-option length check leads to size_t underflow and unbounded OOB heap read","descriptions":[{"lang":"en","value":"RIOT is an open-source microcontroller operating system designed for Internet of Things devices and other embedded systems. Prior to 2026.07, _parse_reply() in sys/net/application_layer/dhcpv6/client.c omits minimum-length validation before passing IA_PD and IA_NA option bodies to sub-option parsers. A malicious or compromised DHCPv6 server can send a REPLY with an option length smaller than the required structure while MODULE_DHCPV6_CLIENT_IA_PD is enabled, causing _parse_ia_pd_option to read past the option body, size_t underflow, and unbounded out-of-bounds heap reads that can crash the device and may expose or corrupt memory. This issue is fixed in version 2026.07."}],"affected":[{"vendor":"RIOT-OS","product":"RIOT","versions":[{"version":"< 2026.07","status":"affected"}]}],"references":[{"url":"https://github.com/RIOT-OS/RIOT/security/advisories/GHSA-p3fx-9qcg-jmcf","name":"https://github.com/RIOT-OS/RIOT/security/advisories/GHSA-p3fx-9qcg-jmcf","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/RIOT-OS/RIOT/pull/22322","name":"https://github.com/RIOT-OS/RIOT/pull/22322","tags":["x_refsource_MISC"]},{"url":"https://github.com/RIOT-OS/RIOT/commit/c9830dc5f2a9bf97418de4fc7d7167d00a45df17","name":"https://github.com/RIOT-OS/RIOT/commit/c9830dc5f2a9bf97418de4fc7d7167d00a45df17","tags":["x_refsource_MISC"]},{"url":"https://github.com/RIOT-OS/RIOT/releases/tag/2026.07","name":"https://github.com/RIOT-OS/RIOT/releases/tag/2026.07","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"HIGH","baseScore":9.8,"baseSeverity":"CRITICAL","confidentialityImpact":"HIGH","integrityImpact":"HIGH","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-125","lang":"en","description":"CWE-125: Out-of-bounds Read","type":"CWE"}]},{"descriptions":[{"cweId":"CWE-191","lang":"en","description":"CWE-191: Integer Underflow (Wrap or Wraparound)","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-10-16T16:50:58.750Z"},"source":{"advisory":"GHSA-p3fx-9qcg-jmcf","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-10-21T02:29:15.518787Z","id":"CVE-2026-49868","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-21T02:29:33.220Z"}}]}}}