Medium
fastnetmon — security advisory
FastNetMon Community Edition through 1.2.9 contains an out-of-bounds read in the NetFlow v9 options template parser. In process_netflow_v9_options_template() (src/netflow_plugin/netflow_v9_collector.cpp), the scope parsing loop (lines 224-229) iterates until scopes_offset reaches the attacker-controlled option_scope_length value, reading netflow9_template_flowset_record_t structures at each step. No bounds check validates that (zone_address + scopes_offset + sizeof(record)) stays within the flowset. The same issue affects the options field loop (lines 241-257) with option_length. Furthermore, option_scope_length is not validated to be a multiple of sizeof(netflow9_template_flowset_record_t), potentially causing misaligned reads. An attacker can trigger reads past the end of the UDP packet buffer.
- Products
- fastnetmon
- Affected versions
- 1.1.3+dfsg-3, 1.1.3+dfsg-4, 1.1.3+dfsg-6build1, 1.1.4-1, 1.1.4-1build3, 1.1.4-1build4, 1.1.4-1build5, 1.1.4-1ubuntu0.1~esm1, 1.2.5-1, 1.2.6-1, 1.2.6-1build1, 1.2.6-1build2, 1.2.6-1build3, 1.2.6-1build4, 1.2.6-1ubuntu0.1~esm1, 1.2.8+git20250911-1, 1.2.8+git20250911-1build1, 1.2.8+git20250911-1build2, 1.2.8+git20250911-2, 1.2.8+git20250911-2ubuntu0.1~esm1, 1.2.8-1build1, 1.2.8-1build2, 1.2.9-1, 1.2.9-1build1, 1.2.9-1build2
- Fixed versions
- Not specified
- CVEs
- CVE-2026-48684
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 31 Oct 2026, 02:21 UTC · Revision 1
Source evidence
FastNetMon Community Edition through 1.2.9 contains an out-of-bounds read in the NetFlow v9 options template parser. In process_netflow_v9_options_template() (src/netflow_plugin/netflow_v9_collector.cpp), the scope parsing loop (lines 224-229) iterates until scopes_offset reaches the attacker-controlled option_scope_length value, reading netflow9_template_flowset_record_t structures at each step. No bounds check validates that (zone_address + scopes_offset + sizeof(record)) stays within the flowset. The same issue affects the options field loop (lines 241-257) with option_length. Furthermore, option_scope_length is not validated to be a multiple of sizeof(netflow9_template_flowset_record_t), potentially causing misaligned reads. An attacker can trigger reads past the end of the UDP packet buffer.
osv:UBUNTU-CVE-2026-48684
fastnetmon
Fixed versions: Not specified
fastnetmon
Fixed versions: Not specified
fastnetmon
Fixed versions: Not specified
fastnetmon
Fixed versions: Not specified
fastnetmon
Fixed versions: Not specified
fastnetmon
Fixed versions: Not specified
Complete source record
{
"id": "7166fa8f3d9d4a8114c398d62e90d892bf00ccb7d859b76771e5a16908b10a29",
"url": "https://osv.dev/vulnerability/UBUNTU-CVE-2026-48684",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "UBUNTU-CVE-2026-48684",
"summary": "FastNetMon Community Edition through 1.2.9 contains an out-of-bounds read in the NetFlow v9 options template parser. In process_netflow_v9_options_template() (src/netflow_plugin/netflow_v9_collector.cpp), the scope parsing loop (lines 224-229) iterates until scopes_offset reaches the attacker-controlled option_scope_length value, reading netflow9_template_flowset_record_t structures at each step. No bounds check validates that (zone_address + scopes_offset + sizeof(record)) stays within the flowset. The same issue affects the options field loop (lines 241-257) with option_length. Furthermore, option_scope_length is not validated to be a multiple of sizeof(netflow9_template_flowset_record_t), potentially causing misaligned reads. An attacker can trigger reads past the end of the UDP packet buffer.",
"evidence": "osv:UBUNTU-CVE-2026-48684",
"products": [
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{
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{
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{
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{
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},
{
"name": {
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"affected_versions": [
{
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{
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"evidence": "/affected/5/versions"
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{
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],
"severity": "medium",
"structured": {
"id": "UBUNTU-CVE-2026-48684",
"aliases": [
"UBUNTU-CVE-2026-48684"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L"
},
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L"
},
{
"type": "Ubuntu",
"score": "medium"
}
],
"affected": [
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
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],
"package": {
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"purl": "pkg:deb/ubuntu/fastnetmon?arch=source&distro=bionic",
"ecosystem": "Ubuntu:18.04:LTS"
},
"versions": [
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"1.1.3+dfsg-4",
"1.1.3+dfsg-6build1"
],
"database_specific": {
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},
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"package": {
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],
"modified": "2026-10-17T12:58:30.175466866Z",
"provider": "osv",
"upstream": [
"CVE-2026-48684"
],
"references": [
"https://ubuntu.com/security/CVE-2026-48684",
"https://www.cve.org/CVERecord?id=CVE-2026-48684",
"https://lorikeetsecurity.com/blog/fastnetmon-cve-2026-48684-netflow-v9-options-oob",
"https://github.com/pavel-odintsov/fastnetmon/commit/aa1069abaa8624e50b5d0c6c8ccd0f5d9ddc111e",
"https://github.com/pavel-odintsov/fastnetmon/pull/1057",
"https://github.com/pavel-odintsov/fastnetmon",
"https://github.com/pavel-odintsov/fastnetmon/blob/master/src/netflow_plugin/netflow_v9_collector.cpp"
]
},
"related_cves": [
{
"value": "CVE-2026-48684",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 358671,
"published_at": "2026-05-26T16:16:00+00:00"
}