---
id: "CVE-2026-92694"
page: "https://infrastack.ai/live/CVE-2026-92694"
kind: "vulnerability"
aliases: ["CVE-2026-92694"]
title: "FastNetMon: IPv6 top-talkers display race can crash the detector"
severity: "medium"
cvss: 5.9
epss: null
exploited: false
status: "open"
category: "other"
products: []
ecosystems: []
tags: ["ddos-detection", "fastnetmon", "ipv6", "other"]
not_affected_if: ["newer-version", "no-ipv6-networks"]
published_at: "2026-11-05T23:17:02+00:00"
first_seen_at: "2026-11-05T23:48:40+00:00"
updated_at: "2026-11-05T23:49:45+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-92694", "first_seen_at": "2026-11-05T23:48:40+00:00"}]
exploit_sources: []
---

# FastNetMon: IPv6 top-talkers display race can crash the detector

Link for people: https://infrastack.ai/live/CVE-2026-92694 (this .md is for agents)

FastNetMon's IPv6 top-talkers screen thread reads a shared map without its lock while another thread inserts into it, causing undefined behavior under load. A crash is plausible, but a reliable denial of service has not been shown.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- Check the installed version with the FastNetMon binary or package manager; versions `1.2.9` and earlier are affected.
- Check whether `networks_list` includes any IPv6 range, since the race needs one to be monitored.

## Timeline

- 2026-11-05T23:48:40+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-92694

## Documents

- [advisory] Vendor advisory: github.com https://github.com/pavel-odintsov/fastnetmon/security/advisories/GHSA-phrw-2q76-5m7h
- [fix] Patch: github.com https://github.com/pavel-odintsov/fastnetmon/commit/1294724ea931dc78fe545360f2193398bba35381

## From the sources

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.

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_Free to read, with fair use of about 60 pages a minute. For higher limits or API access: sales@infrastack.ai_