{"api_version":"1","generated_at":"2026-08-08T07:24:40+00:00","cve":"CVE-2026-5855","urls":{"html":"https://cve.report/CVE-2026-5855","api":"https://cve.report/api/cve/CVE-2026-5855.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-5855","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-5855"},"summary":{"title":"Contiki-NG LwM2M TLV Parser Out-of-Bounds Read via Unchecked Buffer Length in lwm2m_tlv_read","description":"Contiki-NG'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->id, tlv->length, and tlv->value fields. Corrupted tlv_len derived from the out-of-bounds memory further corrupts the caller's parse offset. 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