{"id":"CVE-2026-48686","aliases":["DEBIAN-CVE-2026-48686","EUVD-2026-31842","GHSA-7p7c-c3vp-p386","UBUNTU-CVE-2026-48686","USN-8429-1"],"status":"published","title":"FastNetMon Community Edition through 1.2.9 contains a stack-based buffer overflow in the BGP NLRI...","description":"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 \u003c= 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 \u003e 32 causes undefined behavior.","severity":{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical","assessor":"primary","from":"nvd"},"epss":{"day":"2026-11-09","score":0.00565,"percentile":0.47219,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-120","CWE-787"],"published":"2026-05-26T00:00:00Z","modified":"2026-10-28T02:30:28Z","fixes":[{"ecosystem":"Debian:13","package":"fastnetmon","fixed_in":["1.2.9-0+deb13u1"],"sources":["osv"]},{"ecosystem":"Debian:14","package":"fastnetmon","fixed_in":["1.2.9-1"],"sources":["osv"]},{"ecosystem":"Ubuntu:Pro:24.04:LTS","package":"fastnetmon","fixed_in":["1.2.6-1ubuntu0.1~esm1"],"sources":["osv"]},{"ecosystem":"Ubuntu:Pro:26.04:LTS","package":"fastnetmon","fixed_in":["1.2.8+git20250911-2ubuntu0.1~esm1"],"sources":["osv"]}],"affected":[{"source":"osv","ecosystem":"Debian:12","package":"fastnetmon","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.2.4-2","1.2.4-2+deb12u1","1.2.5-1","1.2.5-2","1.2.5-2~bpo12+1","1.2.6-1","1.2.6-1~bpo12+1","1.2.7-1","1.2.7-1~bpo12+1","1.2.8+git20250911-1","1.2.8+git20250911-2","1.2.8-1","1.2.8-1~bpo12+1","1.2.9-1"]},{"source":"osv","ecosystem":"Debian:13","package":"fastnetmon","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.2.9-0+deb13u1"}]}],"versions":["1.2.8+git20250911-1","1.2.8+git20250911-2","1.2.8-1"]},{"source":"osv","ecosystem":"Debian:14","package":"fastnetmon","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.2.9-1"}]}],"versions":["1.2.8+git20250911-1","1.2.8+git20250911-2","1.2.8-1"]},{"source":"osv","ecosystem":"Ubuntu:Pro:24.04:LTS","package":"fastnetmon","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.2.6-1ubuntu0.1~esm1"}]}],"versions":["1.2.5-1","1.2.6-1","1.2.6-1build1","1.2.6-1build2","1.2.6-1build3","1.2.6-1build4"]},{"source":"osv","ecosystem":"Ubuntu:25.10","package":"fastnetmon","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.2.8-1build1","1.2.8-1build2","1.2.8+git20250911-1"]},{"source":"osv","ecosystem":"Ubuntu:26.10","package":"fastnetmon","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.2.8+git20250911-2","1.2.9-1","1.2.9-1build1","1.2.9-1build2"]},{"source":"osv","ecosystem":"Ubuntu:Pro:26.04:LTS","package":"fastnetmon","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.2.8+git20250911-2ubuntu0.1~esm1"}]}],"versions":["1.2.8+git20250911-1","1.2.8+git20250911-1build1","1.2.8+git20250911-1build2","1.2.8+git20250911-2"]},{"source":"osv","ecosystem":"Ubuntu:Pro:20.04:LTS","package":"fastnetmon","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.1.4-1ubuntu0.1~esm1"}]}],"versions":["1.1.4-1","1.1.4-1build3","1.1.4-1build4","1.1.4-1build5"],"bundled":5},{"source":"osv","ecosystem":"Ubuntu:Pro:24.04:LTS","package":"fastnetmon","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.2.6-1ubuntu0.1~esm1"}]}],"versions":["1.2.5-1","1.2.6-1","1.2.6-1build1","1.2.6-1build2","1.2.6-1build3","1.2.6-1build4"],"bundled":5},{"source":"osv","ecosystem":"Ubuntu:Pro:26.04:LTS","package":"fastnetmon","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.2.8+git20250911-2ubuntu0.1~esm1"}]}],"versions":["1.2.8+git20250911-1","1.2.8+git20250911-1build1","1.2.8+git20250911-1build2","1.2.8+git20250911-2"],"bundled":5}],"products":[{"vendor":"pavel-odintsov","product":"fastnetmon"}],"references":[{"url":"https://github.com/pavel-odintsov/fastnetmon","tags":["Product","package","report"]},{"url":"https://github.com/pavel-odintsov/fastnetmon/blob/master/src/bgp_protocol.cpp","tags":["Product","web","report"]},{"url":"https://lorikeetsecurity.com/blog/fastnetmon-cve-2026-48686-bgp-nlri-stack-overflow","tags":["Third Party Advisory","article","report"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-48686","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-7p7c-c3vp-p386"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/48xxx/CVE-2026-48686.json","tags":["advisory"]},{"url":"https://security-tracker.debian.org/tracker/CVE-2026-48686","tags":["advisory"]},{"url":"https://ubuntu.com/security/CVE-2026-48686","tags":["report"]},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-48686","tags":["report"]},{"url":"https://github.com/pavel-odintsov/fastnetmon/pull/1053","tags":["report"]},{"url":"https://github.com/pavel-odintsov/fastnetmon/commit/265a767635767d7a08391dbe7f98f750d2ea04d0","tags":["report"]},{"url":"https://ubuntu.com/security/notices/USN-8429-1","tags":["advisory"]},{"url":"https://ubuntu.com/security/CVE-2026-48687","tags":["report"]},{"url":"https://ubuntu.com/security/CVE-2026-48689","tags":["report"]},{"url":"https://ubuntu.com/security/CVE-2026-48691","tags":["report"]},{"url":"https://ubuntu.com/security/CVE-2026-48694","tags":["report"]}],"sources":{"cve":[{"id":"CVE-2026-48686","description":"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 \u003c= 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 \u003e 32 causes undefined behavior.","status":"published","published":"2026-05-26T00:00:00Z","modified":"2026-05-26T20:59:11.887Z","cvss":[{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical","assessor":"adp"}],"cwes":["CWE-787","CWE-120"],"updated_at":"2026-11-02T13:50:49.872037Z"}],"euvd":[{"id":"EUVD-2026-31842","description":"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 \u003c= 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 \u003e 32 causes undefined behavior.","status":"published","published":"2026-05-26T00:00:00Z","modified":"2026-05-26T20:59:11Z","cvss":[{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical"}],"updated_at":"2026-11-02T18:21:06.423934Z"}],"ghsa":[{"id":"GHSA-7p7c-c3vp-p386","title":"FastNetMon Community Edition through 1.2.9 contains a stack-based buffer overflow in the BGP NLRI...","description":"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 \u003c= 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 \u003e 32 causes undefined behavior.","status":"published","published":"2026-05-26T18:31:43Z","modified":"2026-05-26T21:32:56Z","cvss":[{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical"}],"cwes":["CWE-120"],"updated_at":"2026-11-02T15:08:18.762226Z"}],"nvd":[{"id":"CVE-2026-48686","description":"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 \u003c= 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 \u003e 32 causes undefined behavior.","status":"published","published":"2026-05-26T16:16:26.693Z","modified":"2026-07-24T11:10:00.17Z","cvss":[{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical","assessor":"primary"},{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical","assessor":"secondary"}],"cwes":["CWE-120","CWE-787"],"updated_at":"2026-11-02T14:12:20.131508Z"}],"osv":[{"id":"CVE-2026-48686","description":"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 \u003c= 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 \u003e 32 causes undefined behavior.","status":"published","published":"2026-05-26T00:00:00Z","modified":"2026-10-28T02:30:28.956376036Z","cvss":[{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical"}],"updated_at":"2026-11-02T15:45:06.701612Z"},{"id":"DEBIAN-CVE-2026-48686","description":"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 \u003c= 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 \u003e 32 causes undefined behavior.","status":"published","published":"2026-05-26T16:16:26.693Z","modified":"2026-10-01T03:03:16.48480439Z","cvss":[{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical"}],"updated_at":"2026-11-02T15:45:56.444225Z"},{"id":"UBUNTU-CVE-2026-48686","description":"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 \u003c= 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 \u003e 32 causes undefined behavior.","status":"published","published":"2026-05-26T16:16:00Z","modified":"2026-10-17T12:58:30.511920739Z","cvss":[{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical"},{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical"}],"updated_at":"2026-11-02T16:56:33.391918Z"},{"id":"USN-8429-1","title":"fastnetmon vulnerabilities","description":"It was discovered that FastNetMon incorrectly validated prefix lengths when\ndecoding BGP NLRI data. A remote attacker could possibly use this issue to\ncause a denial of service or execute arbitrary code. This issue only\naffected Ubuntu 24.04 LTS and Ubuntu 26.04 LTS. (CVE-2026-48686)\n\nIt was discovered that FastNetMon incorrectly sanitized input in the\nJuniper router integration plugin. An attacker could possibly use this\nissue to execute arbitrary commands. (CVE-2026-48687)\n\nIt was discovered that FastNetMon incorrectly handled buffer bounds checks\nwhen processing network traffic. A remote attacker could possibly use this\nissue to cause a denial of service or execute arbitrary code. This issue\nonly affected Ubuntu 24.04 LTS and Ubuntu 26.04 LTS. (CVE-2026-48689)\n\nIt was discovered that FastNetMon incorrectly handled encoding the BGP\nAS_PATH attribute. A remote attacker could possibly use this issue to cause\na denial of service or execute arbitrary code. This issue only affected\nUbuntu 24.04 LTS and Ubuntu 26.04 LTS. (CVE-2026-48691)\n\nIt was discovered that FastNetMon incorrectly validated IP address input in\nthe Juniper router integration plugin. An attacker could possibly use this\nissue to inject arbitrary router configuration commands. (CVE-2026-48694)","status":"published","published":"2026-06-15T16:11:00Z","modified":"2026-06-16T05:14:18.252687362Z","updated_at":"2026-11-02T16:58:25.103481Z"}]}}