{"id":"CVE-2026-71256","state":"PUBLISHED","title":"nanoMODBUS Client-Side Out-of-Bounds Read Leading to Wild-Pointer Write via object_id","description":"nanoMODBUS through v1.23.0 contains an out-of-bounds stack read leading to a wild-pointer write in nmbs_read_device_identification_basic / recv_read_device_identification_res in nanomodbus.c. A fixed 3-element stack array order[3] = {0,1,2} maps object IDs to buffer indices. The server-supplied object_id field (0-255, read directly from the wire) is used without any bounds check as buf_index = order[object_id].","publishedAt":"2026-08-05T11:44:21.992Z","updatedAt":"2026-08-10T11:46:18.081Z","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":"TuranSec"},"assigner":"TuranSec","products":["debevv nanoMODBUS"],"affected":[{"vendor":"debevv","product":"nanoMODBUS","defaultStatus":"unaffected","versions":[{"version":"0","status":"affected","lessThanOrEqual":"1.23.0","versionType":"semver"}],"programFiles":["nanomodbus.c"]}],"references":["https://github.com/debevv/nanoMODBUS","https://github.com/debevv/nanoMODBUS/blob/master/nanomodbus.c"],"weaknesses":["CWE-125"],"ingestedAt":"2026-10-29T20:12:49.727Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/71xxx/CVE-2026-71256.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-71256","state":"PUBLISHED","datePublished":"2026-08-05T11:44:21.992Z","dateUpdated":"2026-08-10T11:46:18.081Z","assignerShortName":"TuranSec","assignerOrgId":"309f9ea4-e3e9-4c6c-b79d-e8eb01244f2c","dateReserved":"2026-08-05T11:43:52.778Z"},"containers":{"cna":{"title":"nanoMODBUS Client-Side Out-of-Bounds Read Leading to Wild-Pointer Write via object_id","descriptions":[{"lang":"en","value":"nanoMODBUS through v1.23.0 contains an out-of-bounds stack read leading to a wild-pointer write in nmbs_read_device_identification_basic / recv_read_device_identification_res in nanomodbus.c. A fixed 3-element stack array order[3] = {0,1,2} maps object IDs to buffer indices. The server-supplied object_id field (0-255, read directly from the wire) is used without any bounds check as buf_index = order[object_id]."}],"affected":[{"vendor":"debevv","product":"nanoMODBUS","defaultStatus":"unaffected","versions":[{"version":"0","status":"affected","lessThanOrEqual":"1.23.0","versionType":"semver"}],"programFiles":["nanomodbus.c"]}],"references":[{"url":"https://github.com/debevv/nanoMODBUS","tags":["third-party-advisory"]},{"url":"https://github.com/debevv/nanoMODBUS/blob/master/nanomodbus.c","tags":["third-party-advisory"]}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","baseScore":9.8,"baseSeverity":"CRITICAL","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"HIGH"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-125","lang":"en","description":"CWE-125","type":"CWE"}]}],"providerMetadata":{"shortName":"TuranSec","orgId":"309f9ea4-e3e9-4c6c-b79d-e8eb01244f2c","dateUpdated":"2026-08-10T11:46:18.081Z"},"credits":[{"lang":"en","value":"Shukhratbek Uraiimov","type":"finder"}],"source":{"discovery":"EXTERNAL"},"datePublic":"2026-08-05T11:44:21.992Z"},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-08-05T12:25:23.617290Z","id":"CVE-2026-71256","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"total"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-08-05T12:26:11.018Z"}}]}}}