{"id":"CVE-2026-102692","published":"2026-10-16T17:17:16.980","lastModified":"2026-10-16T22:17:08.800","description":"RIOT is an open-source microcontroller operating system designed for Internet of Things devices and other embedded systems. Prior to 2026.07, nanocoap accepts oversized CoAP Block2 option values without enforcing the 20-bit maximum block number, allowing block offset multiplication to overflow on 32-bit targets. The affected master baseline is commit aeeae69e; the verified fix is later on master and remains unreleased. The oversized value passes from coap_get_blockopt() to coap_block_slicer_init(). A remote CoAP client can send a malformed Block2 option that produces an invalid slice range and can cause out-of-bounds memory access, denial of service, or memory corruption. This vulnerability is fixed in 2026.07.","cvssScore":9.1,"cvssSeverity":"CRITICAL","cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H","cwes":["CWE-190","CWE-787"],"vendors":[],"products":[],"references":[{"url":"https://github.com/RIOT-OS/RIOT/commit/6b283ace3565d931b3edff7e115d4f79339253b8","tags":[]},{"url":"https://github.com/RIOT-OS/RIOT/commit/ee1fa0ef91874494823d476392572aeefdbc6b74","tags":[]},{"url":"https://github.com/RIOT-OS/RIOT/releases/tag/2026.07","tags":[]},{"url":"https://github.com/RIOT-OS/RIOT/security/advisories/GHSA-8365-gj33-rgpf","tags":[]}],"exploitRefs":[{"url":"https://github.com/RIOT-OS/RIOT/commit/6b283ace3565d931b3edff7e115d4f79339253b8","tags":[]},{"url":"https://github.com/RIOT-OS/RIOT/commit/ee1fa0ef91874494823d476392572aeefdbc6b74","tags":[]},{"url":"https://github.com/RIOT-OS/RIOT/releases/tag/2026.07","tags":[]},{"url":"https://github.com/RIOT-OS/RIOT/security/advisories/GHSA-8365-gj33-rgpf","tags":[]}],"hasPoc":true,"ai":{"summary":"RIOT OS's nanocoap component fails to validate CoAP Block2 option block numbers, allowing 32-bit integer overflow when calculating block offsets. This can lead to out-of-bounds memory access, denial of service, or memory corruption in IoT devices.","exploitability":"Exploitation is relatively straightforward for remote attackers who can send malformed CoAP packets to vulnerable RIOT devices, requiring no authentication or user interaction.","blast_radius":"The vulnerability affects IoT devices running RIOT OS versions prior to 2026.07, potentially impacting a wide range of embedded systems including sensors, actuators, and networked appliances.","remediation":"Upgrade to RIOT OS version 2026.07 or later to receive the fix for the CoAP Block2 option validation vulnerability.","detection":"No reliable host or network indicator is derivable from the published description.","tags":["iot","coap","memory-corruption"],"model":"garnet-coder","analyzedAt":"2026-10-17T08:49:11.949Z"}}