CVE-2026-48686

{"dataType": "CVE_RECORD", "cveMetadata": {"state": "PUBLISHED", "cveId": "CVE-2026-48686", "assignerOrgId": "8254265b-2729-46b6-b9e3-3dfca2d5bfca", "assignerShortName": "mitre", "dateUpdated": "2026-05-26T20:59:11.887Z", "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": "2026-05-26T14:46:38.784Z"}, "descriptions": [{"lang": "en", "value": "FastNetMon Community Edition through 1.2.9 contains a stack-based buffer overflow in the BGP NLRI (Network Layer Reachability Information) decoder. The function decode_bgp_subnet_encoding_ipv4_raw() in src/bgp_protocol.cpp reads prefix_bit_length directly from the BGP packet (line 99) without validating it is <= 32 for IPv4 prefixes. This value is passed to how_much_bytes_we_need_for_storing_certain_subnet_mask() which computes ceil(prefix_bit_length / 8), returning up to 32 bytes for a prefix_bit_length of 255. The result is used as the length argument to memcpy() (line 106), which copies into a 4-byte uint32_t stack variable (prefix_ipv4). This causes a stack buffer overflow of up to 28 bytes, which can be exploited for arbitrary code execution. Additionally, the unvalidated prefix_bit_length is passed to convert_cidr_to_binary_netmask_local_function_copy() (line 111), where a shift of (32 - cidr) with cidr > 32 causes undefined behavior."}], "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/bgp_protocol.cpp"}, {"url": "https://lorikeetsecurity.com/blog/fastnetmon-cve-2026-48686-bgp-nlri-stack-overflow"}], "problemTypes": [{"descriptions": [{"type": "text", "lang": "en", "description": "n/a"}]}]}, "adp": [{"problemTypes": [{"descriptions": [{"type": "CWE", "cweId": "CWE-787", "lang": "en", "description": "CWE-787 Out-of-bounds Write"}]}, {"descriptions": [{"type": "CWE", "cweId": "CWE-120", "lang": "en", "description": "CWE-120 Buffer Copy without Checking Size of Input ('Classic 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": "2026-05-26T20:58:47.062692Z", "id": "CVE-2026-48686", "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": "2026-05-26T20:59:11.887Z"}}]}, "dataVersion": "5.2"}

{"dataType": "CVE_RECORD", "cveMetadata": {"state": "PUBLISHED", "cveId": "CVE-2026-48686", "assignerOrgId": "8254265b-2729-46b6-b9e3-3dfca2d5bfca", "assignerShortName": "mitre", "dateUpdated": "2026-05-26T20:59:11.887Z", "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": "2026-05-26T14:46:38.784Z"}, "descriptions": [{"lang": "en", "value": "FastNetMon Community Edition through 1.2.9 contains a stack-based buffer overflow in the BGP NLRI (Network Layer Reachability Information) decoder. The function decode_bgp_subnet_encoding_ipv4_raw() in src/bgp_protocol.cpp reads prefix_bit_length directly from the BGP packet (line 99) without validating it is <= 32 for IPv4 prefixes. This value is passed to how_much_bytes_we_need_for_storing_certain_subnet_mask() which computes ceil(prefix_bit_length / 8), returning up to 32 bytes for a prefix_bit_length of 255. The result is used as the length argument to memcpy() (line 106), which copies into a 4-byte uint32_t stack variable (prefix_ipv4). This causes a stack buffer overflow of up to 28 bytes, which can be exploited for arbitrary code execution. Additionally, the unvalidated prefix_bit_length is passed to convert_cidr_to_binary_netmask_local_function_copy() (line 111), where a shift of (32 - cidr) with cidr > 32 causes undefined behavior."}], "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/bgp_protocol.cpp"}, {"url": "https://lorikeetsecurity.com/blog/fastnetmon-cve-2026-48686-bgp-nlri-stack-overflow"}], "problemTypes": [{"descriptions": [{"type": "text", "lang": "en", "description": "n/a"}]}]}, "adp": [{"title": "CISA ADP Vulnrichment", "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": {"id": "CVE-2026-48686", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "yes"}, {"Technical Impact": "total"}], "version": "2.0.3", "timestamp": "2026-05-26T20:58:47.062692Z"}}}], "problemTypes": [{"descriptions": [{"lang": "en", "type": "CWE", "cweId": "CWE-787", "description": "CWE-787 Out-of-bounds Write"}]}, {"descriptions": [{"lang": "en", "type": "CWE", "cweId": "CWE-120", "description": "CWE-120 Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')"}]}], "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-05-26T20:59:08.823Z"}}]}, "dataVersion": "5.2"}

{"affected": [{"affectedData": [{"product": "n/a", "vendor": "n/a", "versions": [{"status": "affected", "version": "n/a"}]}], "source": "cve@mitre.org"}], "configurations": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:a:pavel-odintsov:fastnetmon:*:*:*:*:community:*:*:*", "matchCriteriaId": "E712A01F-3AD7-4CC2-9A8B-F8C63756EBBF", "versionEndIncluding": "1.2.9", "vulnerable": true}], "negate": false, "operator": "OR"}]}], "cveTags": [], "descriptions": [{"lang": "en", "value": "FastNetMon Community Edition through 1.2.9 contains a stack-based buffer overflow in the BGP NLRI (Network Layer Reachability Information) decoder. The function decode_bgp_subnet_encoding_ipv4_raw() in src/bgp_protocol.cpp reads prefix_bit_length directly from the BGP packet (line 99) without validating it is <= 32 for IPv4 prefixes. This value is passed to how_much_bytes_we_need_for_storing_certain_subnet_mask() which computes ceil(prefix_bit_length / 8), returning up to 32 bytes for a prefix_bit_length of 255. The result is used as the length argument to memcpy() (line 106), which copies into a 4-byte uint32_t stack variable (prefix_ipv4). This causes a stack buffer overflow of up to 28 bytes, which can be exploited for arbitrary code execution. Additionally, the unvalidated prefix_bit_length is passed to convert_cidr_to_binary_netmask_local_function_copy() (line 111), where a shift of (32 - cidr) with cidr > 32 causes undefined behavior."}, {"lang": "es", "value": "FastNetMon Community Edition hasta la versi\u00f3n 1.2.9 contiene un desbordamiento de b\u00fafer basado en pila en el decodificador BGP NLRI (Informaci\u00f3n de Alcance de Capa de Red). La funci\u00f3n decode_bgp_subnet_encoding_ipv4_raw() en src/bgp_protocol.cpp lee prefix_bit_length directamente del paquete BGP (l\u00ednea 99) sin validar que sea <= 32 para prefijos IPv4. Este valor se pasa a how_much_bytes_we_need_for_storing_certain_subnet_mask() que calcula ceil(prefix_bit_length / 8), devolviendo hasta 32 bytes para un prefix_bit_length de 255. El resultado se utiliza como argumento de longitud para memcpy() (l\u00ednea 106), que copia en una variable de pila uint32_t de 4 bytes (prefix_ipv4). Esto causa un desbordamiento de b\u00fafer basado en pila de hasta 28 bytes, que puede ser explotado para ejecuci\u00f3n de c\u00f3digo arbitrario. Adem\u00e1s, el prefix_bit_length no validado se pasa a convert_cidr_to_binary_netmask_local_function_copy() (l\u00ednea 111), donde un desplazamiento de (32 - cidr) con cidr > 32 causa un comportamiento indefinido."}], "id": "CVE-2026-48686", "lastModified": "2026-07-24T11:10:00.170", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 9.8, "baseSeverity": "CRITICAL", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", "version": "3.1"}, "exploitabilityScore": 3.9, "impactScore": 5.9, "source": "nvd@nist.gov", "type": "Primary"}, {"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 9.8, "baseSeverity": "CRITICAL", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", "version": "3.1"}, "exploitabilityScore": 3.9, "impactScore": 5.9, "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-48686", "options": [{"exploitation": "none"}, {"automatable": "yes"}, {"technicalImpact": "total"}], "role": "CISA Coordinator", "timestamp": "2026-05-26T20:58:47.062692Z", "version": "2.0.3"}}]}, "published": "2026-05-26T16:16:26.693", "references": [{"source": "cve@mitre.org", "tags": ["Product"], "url": "https://github.com/pavel-odintsov/fastnetmon"}, {"source": "cve@mitre.org", "tags": ["Product"], "url": "https://github.com/pavel-odintsov/fastnetmon/blob/master/src/bgp_protocol.cpp"}, {"source": "cve@mitre.org", "tags": ["Third Party Advisory"], "url": "https://lorikeetsecurity.com/blog/fastnetmon-cve-2026-48686-bgp-nlri-stack-overflow"}], "sourceIdentifier": "cve@mitre.org", "vulnStatus": "Analyzed", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-120"}, {"lang": "en", "value": "CWE-787"}], "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary"}]}

{}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[0,1.2.9]"}}], "enrichment": {"confidence": 85.0, "confidence_source": "inferred", "scores": [{"score": 85.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "n/a", "source": "cna", "vendor": "n/a"}, "product": "fastnetmon", "vendor": "pavel-odintsov"}], "created": "2026-05-26T16:30:09.738603+00:00", "updated": "2026-05-26T23:45:06.258078+00:00", "vendors": ["pavel-odintsov", "pavel-odintsov$PRODUCT$fastnetmon"]}