CVE-2026-71263

{"id": "CVE-2026-71263", "cveTags": [], "metrics": {"ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-71263", "role": "CISA Coordinator", "options": [{"exploitation": "none"}, {"automatable": "yes"}, {"technicalImpact": "partial"}], "version": "2.0.3", "timestamp": "2026-08-05T15:39:27.280961Z"}}], "cvssMetricV31": [{"type": "Secondary", "source": "309f9ea4-e3e9-4c6c-b79d-e8eb01244f2c", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 9.1, "attackVector": "NETWORK", "baseSeverity": "CRITICAL", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H", "integrityImpact": "HIGH", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "NONE", "confidentialityImpact": "NONE"}, "impactScore": 5.2, "exploitabilityScore": 3.9}]}, "affected": [{"source": "309f9ea4-e3e9-4c6c-b79d-e8eb01244f2c", "affectedData": [{"vendor": "cwalter-at", "product": "FreeModbus", "versions": [{"status": "affected", "version": "0", "versionType": "custom", "lessThanOrEqual": "*"}], "programFiles": ["demo/LINUXTCP/port/porttcp.c"], "defaultStatus": "unaffected"}]}], "published": "2026-08-05T13:24:50.473", "references": [{"url": "https://github.com/cwalter-at/freemodbus", "source": "309f9ea4-e3e9-4c6c-b79d-e8eb01244f2c"}, {"url": "https://github.com/cwalter-at/freemodbus/blob/master/demo/LINUXTCP/port/porttcp.c", "source": "309f9ea4-e3e9-4c6c-b79d-e8eb01244f2c"}], "vulnStatus": "Deferred", "weaknesses": [{"type": "Secondary", "source": "309f9ea4-e3e9-4c6c-b79d-e8eb01244f2c", "description": [{"lang": "en", "value": "CWE-787"}]}], "descriptions": [{"lang": "en", "value": "The LINUXTCP port of FreeModbus contains an off-by-one bounds check in xMBPortTCPPool (demo/LINUXTCP/port/porttcp.c). The check uses a strict greater-than comparison instead of greater-than-or-equal against the 263-byte MB_TCP_BUF_SIZE limit."}], "lastModified": "2026-08-26T17:13:24.800", "sourceIdentifier": "309f9ea4-e3e9-4c6c-b79d-e8eb01244f2c"}