Vulnerability Description
FastNetMon Community Edition through 1.2.9 contains an out-of-bounds read vulnerability in the NetFlow v9 data flowset processor. In src/netflow_plugin/netflow_v9_collector.cpp, the Data template branch (lines 1695-1702) iterates over flow records without performing a per-iteration bounds check against the packet end pointer. In contrast, the Options template branch (lines 1709-1719) correctly checks 'if (pkt + offset + field_template->total_length > packet_end)' before each iteration. The Data branch omits this check entirely. Since template definitions are sent by the network peer (and are unauthenticated UDP), an attacker can craft templates that cause the parser to read arbitrary memory past the packet buffer. This can leak sensitive memory contents or cause a crash.
CVSS Score
MEDIUM
Related Weaknesses (CWE)
References
- https://github.com/pavel-odintsov/fastnetmon
- https://github.com/pavel-odintsov/fastnetmon/blob/master/src/netflow_plugin/netf
- https://lorikeetsecurity.com/blog/fastnetmon-cve-2026-48683-netflow-v9-data-oob
FAQ
What is CVE-2026-48683?
CVE-2026-48683 is a vulnerability with a CVSS score of 6.5 (MEDIUM). FastNetMon Community Edition through 1.2.9 contains an out-of-bounds read vulnerability in the NetFlow v9 data flowset processor. In src/netflow_plugin/netflow_v9_collector.cpp, the Data template bran...
How severe is CVE-2026-48683?
CVE-2026-48683 has been rated MEDIUM with a CVSS base score of 6.5/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-48683?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.