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.
{
"cna_assigner": "GitHub_M",
"cwe_ids": [
"CWE-190",
"CWE-787"
],
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/102xxx/CVE-2026-102692.json"
}