CVE-2026-48684

CVE-2026-48684 is a medium-severity vulnerability in Pavel-odintsov Fastnetmon with a CVSS 3.x base score of 6.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-125.

Key facts

Description

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.

Frequently asked questions

What is CVE-2026-48684?
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.
How severe is CVE-2026-48684?
CVE-2026-48684 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity none, and availability low.
Is CVE-2026-48684 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (18th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-48684?
CVE-2026-48684 affects Pavel-odintsov Fastnetmon. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-48684?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-48684 have an EU (EUVD) identifier?
Yes. CVE-2026-48684 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-31840.
When was CVE-2026-48684 published?
CVE-2026-48684 was published on 2026-05-26 and last updated on 2026-06-17.

References

Affected products (1)

More vulnerabilities in Pavel-odintsov Fastnetmon

All CVEs affecting Pavel-odintsov Fastnetmon →

Other CWE-125 (Out-of-bounds Read) vulnerabilities

Browse all CWE-125 (Out-of-bounds Read) vulnerabilities →