{"id":5070,"date":"2026-09-04T18:46:58","date_gmt":"2026-09-04T10:46:58","guid":{"rendered":"https:\/\/www.54iter.cn\/?vuln=cve-2026-5855"},"modified":"2026-09-04T18:46:58","modified_gmt":"2026-09-04T10:46:58","slug":"cve-2026-5855","status":"publish","type":"vuln","link":"https:\/\/www.54iter.cn\/?vuln=cve-2026-5855","title":{"rendered":"CVE-2026-5855 [HIGH] &#8211; Contiki-NG&#8217;s LwM2M TLV parser lwm2m_tlv_read() in os\/services\/lwm2m\/lwm2m-tlv.c ignores it"},"content":{"rendered":"<p>Contiki-NG&#8217;s LwM2M TLV parser lwm2m_tlv_read() in os\/services\/lwm2m\/lwm2m-tlv.c ignores its caller-supplied buffer length argument and reads up to six bytes from the input buffer with no bounds check. The caller in lwm2m-engine.c iterates while there is at least one byte remaining, so a crafted CoAP WRITE to any LwM2M endpoint whose final TLV supplies exactly one byte triggers up to five out-of-bounds reads of heap memory adjacent to the CoAP input buffer, disclosing memory contents (including key material and peer addresses) through the parsed tlv-&gt;id, tlv-&gt;length, and tlv-&gt;value fields. Corrupted tlv_len derived from the out-of-bounds memory further corrupts the caller&#8217;s parse offset. In LwM2M NoSec mode, the default for constrained devices, no authentication is required.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Contiki-NG&#8217;s LwM2M TLV parser lwm2m_tlv_read() in os\/services\/lwm2m\/lwm2m-tlv.c ignores its caller-supplied buffer length argument and reads up to six bytes from the input buffer with no bounds check.<\/p>\n","protected":false},"template":"","meta":[],"categories":[],"tags":[],"class_list":["post-5070","vuln","type-vuln","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln\/5070","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln"}],"about":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/types\/vuln"}],"wp:attachment":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=5070"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=5070"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=5070"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}