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Fencer Vulns
medium 5.9

CVE-2026-92694 json

FastNetMon: IPv6 host counters map iterated without lock, racing concurrent inserts

published 2026-11-05 3 d ago modified 2026-11-05 3 d ago also EUVD-2026-117832

cvss
5.9
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 16%
public exploits
0
none known

Summary

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.

Patch / fix

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-92694 updated cvss 5.9

fastnetmon: FastNetMon: Denial of Service via race condition in IPv6 traffic monitoring

  • Red Hat All currently supported Red Hat products
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

0.25% chance of exploitation in the next 30 days, higher than 16% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 5.9 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected products

  • pavel-odintsov fastnetmon

Classification

Weakness
  • CWE-362 Concurrent Execution using Shared Resource with Improper Synchronization

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.