When MELSOFT transmission port (UDP/IP) of Mitsubishi Electric MELSEC iQ-R series (all versions), MELSEC iQ-F series (all versions), MELSEC…

published 2020-03-30 6 y ago modified 2026-06-17 4 mo ago also EUVD-2020-26690

cvss: 7.5; version 3.1, NVD
cisa kev: Not listed; not in CISA's catalog
epss: 1.4%; EPSS 1.4% chance of exploitation in 30 days, percentile 71%
public exploits: 0; none known

When MELSOFT transmission port (UDP/IP) of Mitsubishi Electric MELSEC iQ-R series (all versions), MELSEC iQ-F series (all versions), MELSEC Q series (all versions), MELSEC L series (all versions), and MELSEC F series (all versions) receives massive amount of data via unspecified vectors, resource consumption occurs and the port does not process the data properly. As a result, it may fall into a denial-of-service (DoS) condition. The vendor states this vulnerability only affects Ethernet communication functions.

Vendor advisories

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

cisa ICSA-20-091-02 updated 2020-03-31 cvss 5.3

Mitsubishi Electric MELSEC

Mitsubishi Electric MELSEC iQ-R iQ-F Q L and F series
affected: mitigation “In the user manual for this device, Mitsubishi Electric recommends implementing one or both of the following: Install a firewall. Use the IP filter function to restrict the connectable IP addresses.” us.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

1.36% chance of exploitation in the next 30 days, higher than 71% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
NVD	3.1	7.5	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD	2.0	5.0	AV:N/AC:L/Au:N/C:N/I:N/A:P

Affected products

Mitsubishi Electric Corporation MELSOFT transmission port (UDP/IP) of multiple Mitsubishi Electric MELSEC series

Classification

Weakness

CWE-400 Uncontrolled Resource Consumption

References

mitsubishielectric.com /en/psirt/vulnerability/pdf/2019-005_en.pdf
vendor-advisory
jvn.jp /en/vu/JVNVU91553662/index.html
third-party-advisory

Sources

CVE List CVE-2020-5527
NVD CVE-2020-5527

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.

Summary