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Fencer Vulns
high 7.4

CVE-2020-5665 json

Improper check or handling of exceptional conditions in MELSEC iQ-F series FX5U(C) CPU unit firmware version 1.060 and earlier allows an at…

published 2020-12-14 5 y ago modified 2026-06-17 4 mo ago also EUVD-2020-26826

cvss
7.4
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
1.0%
EPSS 1.0% chance of exploitation in 30 days, percentile 63%
public exploits
0
none known

Summary

Improper check or handling of exceptional conditions in MELSEC iQ-F series FX5U(C) CPU unit firmware version 1.060 and earlier allows an attacker to cause a denial-of-service (DoS) condition on program execution and communication by sending a specially crafted ARP packet.

Vendor advisories

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

cisa ICSA-20-345-01 updated cvss 7.4

Mitsubishi Electric MELSEC iQ-F Series

  • Mitsubishi Electric MELSEC iQ-F Series <= 1.060
    affected: mitigation “Mitsubishi Electric recommends users update firmware to Version 1.061 or later.” mitsubishielectric.com

From CISA ICS and IT advisories (CSAF, https://github.com/cisagov/CSAF), a U.S. Government work; changed: reduced to products, statuses and remediations. CISA notification · csaf

Exploit prediction

1.03% chance of exploitation in the next 30 days, higher than 63% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 3.1 7.4 CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
NVD 2.0 3.3 AV:A/AC:L/Au:N/C:N/I:N/A:P

Affected products

  • Mitsubishi Electric Corporation MELSEC iQ-F series FX5U(C) CPU unit

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.