CVE-2026-93424: high-severity vulnerability in pavel-odintsov fastnetmon
FastNetMon: NetFlow/IPFIX template cache returns unlocked pointers, causing heap-use-after-free on multi-port deployments
Published
E-mail alert when it lands in KEV, gets a public PoC or its score goes up.
21Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 7.5epss 0.3%
FastNetMon is a high-performance DDoS detector and sensor. In version 1.2.9 and earlier, peer_find_template() in src/netflow_plugin/netflow_collector.cpp and src/netflow_plugin/netflow_v9_collector.cpp returns a pointer into global_netflow9_templates after releasing the cache mutex. On deployments with at least two entries in netflow_ports, concurrent template redefinition and data-flowset processing can let add_update_peer_template() reassign the template and free its records vector while another listener dereferences the escaped pointer. An unauthenticated sender that can reach both NetFlow/IPFIX listener ports can trigger a heap-use-after-free and reliably crash FastNetMon. No fixed release is available as of this review.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Affected products
pavel-odintsov · fastnetmonRelated CVEs — pavel-odintsov fastnetmon
In the same product, most dangerous first.
CVE-2026-92697HIGHFastNetMon: NetFlow v9 unbounded strlen() on interface-description field causes remote out-of-bounds readEPSS 1.1%CVE-2026-92698HIGHFastNetMon: sFlow header_size field trusted as parser capture length causes remote out-of-bounds readEPSS 0.3%CVE-2026-92693HIGHFastNetMon: IPv6 Fragment header dereferenced without bounds check in shared packet parserEPSS 0.3%CVE-2026-92695HIGHFastNetMon: Legacy pcap parse_packet() has no bounds checking, causing out-of-bounds read on truncated framesEPSS 0.3%CVE-2026-92694MEDIUMFastNetMon: IPv6 host counters map iterated without lock, racing concurrent insertsEPSS 0.2%