{"dataType":"CVE_RECORD","cveMetadata":{"state":"PUBLISHED","cveId":"CVE-2026-48689","assignerOrgId":"8254265b-2729-46b6-b9e3-3dfca2d5bfca","assignerShortName":"mitre","dateUpdated":"2026-05-27T00:20:18.668Z","dateReserved":"2026-05-22T00:00:00.000Z","datePublished":"2026-05-26T00:00:00.000Z"},"containers":{"cna":{"providerMetadata":{"orgId":"8254265b-2729-46b6-b9e3-3dfca2d5bfca","shortName":"mitre","dateUpdated":"2026-05-26T18:46:33.597Z"},"descriptions":[{"lang":"en","value":"FastNetMon Community Edition through 1.2.9 contains an off-by-one heap-based buffer overflow in the dynamic_binary_buffer_t class (src/dynamic_binary_buffer.hpp). Five methods (append_dynamic_buffer, append_data_as_pointer, append_data_as_object_ptr, memcpy_from_ptr, memcpy_from_object_ptr) use an incorrect bounds check of the form 'if (offset + length > maximum_internal_storage_size + 1)' instead of the correct 'if (offset + length > maximum_internal_storage_size)'. This allows writing exactly one byte past the end of the heap-allocated buffer. The class is used pervasively in BGP message encoding/decoding, NetFlow template processing, and Flow Spec NLRI construction. An attacker who can send network traffic (NetFlow, sFlow, IPFIX, or BGP) to a FastNetMon instance can trigger this overflow, potentially achieving arbitrary code execution by corrupting heap metadata. Notably, the append_byte() method uses the correct bounds check, confirming the inconsistency."}],"affected":[{"vendor":"n/a","product":"n/a","versions":[{"version":"n/a","status":"affected"}]}],"references":[{"url":"https://github.com/pavel-odintsov/fastnetmon"},{"url":"https://github.com/pavel-odintsov/fastnetmon/blob/master/src/dynamic_binary_buffer.hpp"},{"url":"https://lorikeetsecurity.com/blog/fastnetmon-cve-2026-48689-dynamic-buffer-off-by-one"}],"problemTypes":[{"descriptions":[{"type":"text","lang":"en","description":"n/a"}]}]},"adp":[{"problemTypes":[{"descriptions":[{"type":"CWE","cweId":"CWE-193","lang":"en","description":"CWE-193 Off-by-one Error"}]},{"descriptions":[{"type":"CWE","cweId":"CWE-122","lang":"en","description":"CWE-122 Heap-based Buffer Overflow"}]}],"metrics":[{"cvssV3_1":{"scope":"UNCHANGED","version":"3.1","baseScore":9.8,"attackVector":"NETWORK","baseSeverity":"CRITICAL","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","integrityImpact":"HIGH","userInteraction":"NONE","attackComplexity":"LOW","availabilityImpact":"HIGH","privilegesRequired":"NONE","confidentialityImpact":"HIGH"}},{"other":{"type":"ssvc","content":{"timestamp":"2026-05-27T00:20:15.356833Z","id":"CVE-2026-48689","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"total"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"title":"CISA ADP Vulnrichment","providerMetadata":{"orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP","dateUpdated":"2026-05-27T00:20:18.668Z"}}]},"dataVersion":"5.2"}