Vulnerability · Published Nov 5, 2026 · Assigned by GitHub_M
CVE-2026-92694FastNetMon: IPv6 host counters map iterated without lock, racing concurrent inserts
Medium 5.9
In plain English
A medium-severity race condition in fastnetmon from pavel-odintsov. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 16% of all known vulnerabilities).
Official description
FastNetMon is a high-performance DDoS detector and sensor. In version 1.2.9 and earlier, FastNetMon's IPv6 top-talkers screen-draw thread in draw_table_ipv6() in src/fastnetmon_logic.cpp iterates ipv6_host_counters.average_speed_map without holding counter_map_mutex while recalculate_speed() inserts new keys and may rehash the same map. The race requires networks_list to include the targeted IPv6 range. It causes confirmed undefined behavior under load; a process crash is plausible but was not observed, so reliable denial of service has not been established. No fixed release is available as of this review.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | fastnetmon | no fix listed | DEBIAN-CVE-2026-92694 |
| Debian:13 | fastnetmon | no fix listed | DEBIAN-CVE-2026-92694 |
| Debian:14 | fastnetmon | no fix listed | DEBIAN-CVE-2026-92694 |
| Ubuntu:26.10 | fastnetmon | no fix listed | UBUNTU-CVE-2026-92694 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| pavel-odintsov | fastnetmon | <= 1.2.9 |
Weakness: CWE-362 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H