CVE-2020-5527

mediumpriority · track · 30EPSS 0.014 · 72 %ileEUUS

grimoire priorityP3 · Track

Exploitable?

—

no known exploitation

Likely / severe?

1.36% (72nd) EPSS

CVSS 5 · medium

Is it mine?

49 products

Check your exposure

Who says so?

4 sources

cnnvd · enisa_euvd · cisa_csaf_ot · nvd

EPSS · scored 2026-10-27

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.

remediations

Vendor fix, mitigation, or workaround guidance, as published by each source.

No vendor fix yet; a mitigation is available.

MitigationMELSEC iQ-R iQ-F Q L and F seriescisa_csaf_ot
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.

cvss

Technical severity, 0–10. One row per scoring source.

7.5

010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 5–7.5

v2.05mediumAV:N/AC:L/Au:N/C:N/I:N/A:Pprimary · NVD / NIST USexploitability 10 · impact 2.9

v3.17.5highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:Hprimary · NVD / NIST USexploitability 3.9 · impact 3.6

v3.05.3mediumCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:Lsecondary · CISA US

v3.16.9mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:Usecondary · CVSS-BT (t0sche)

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-400USprimaryCWE-400US

affected products (49)

Products and version ranges known to be affected.

MELSEC iQ-R iQ-F Q L and F series: all versionsall versionscisa_csaf_otUS
Mitsubishi Electric MELSEC iQ-R iQ-F Q L and F seriesall versionscisa_csaf_otUS
Mitsubishi Electric Corporation MELSOFT transmission port (UDP/IP) of multiple Mitsubishi Electric MELSEC series≤ 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)enisa_euvdEU
mitsubishielectric cr800-q firmwareall versionsnvdUScpe:2.3:o:mitsubishielectric:cr800-q_firmware:*:*:*:*:*:*:*:*
mitsubishielectric fx3g firmwareall versionsnvdUScpe:2.3:o:mitsubishielectric:fx3g_firmware:*:*:*:*:*:*:*:*
mitsubishielectric fx3gc firmwareall versionsnvdUScpe:2.3:o:mitsubishielectric:fx3gc_firmware:*:*:*:*:*:*:*:*
mitsubishielectric fx3s firmwareall versionsnvdUScpe:2.3:o:mitsubishielectric:fx3s_firmware:*:*:*:*:*:*:*:*
mitsubishielectric fx3u firmwareall versionsnvdUScpe:2.3:o:mitsubishielectric:fx3u_firmware:*:*:*:*:*:*:*:*
mitsubishielectric fx3uc firmwareall versionsnvdUScpe:2.3:o:mitsubishielectric:fx3uc_firmware:*:*:*:*:*:*:*:*
mitsubishielectric fx5u firmwareall versionsnvdUScpe:2.3:o:mitsubishielectric:fx5u_firmware:*:*:*:*:*:*:*:*
mitsubishielectric fx5uc firmwareall versionsnvdUScpe:2.3:o:mitsubishielectric:fx5uc_firmware:*:*:*:*:*:*:*:*
mitsubishielectric fx5uj firmwareall versionsnvdUScpe:2.3:o:mitsubishielectric:fx5uj_firmware:*:*:*:*:*:*:*:*
mitsubishielectric l02cpu firmwareall versionsnvdUScpe:2.3:o:mitsubishielectric:l02cpu_firmware:*:*:*:*:*:*:*:*
mitsubishielectric l02cpu-p firmwareall versionsnvdUScpe:2.3:o:mitsubishielectric:l02cpu-p_firmware:*:*:*:*:*:*:*:*
mitsubishielectric l02scpu firmwareall versionsnvdUScpe:2.3:o:mitsubishielectric:l02scpu_firmware:*:*:*:*:*:*:*:*
mitsubishielectric l02scpu-p firmwareall versionsnvdUScpe:2.3:o:mitsubishielectric:l02scpu-p_firmware:*:*:*:*:*:*:*:*
mitsubishielectric l06cpu firmwareall versionsnvdUScpe:2.3:o:mitsubishielectric:l06cpu_firmware:*:*:*:*:*:*:*:*
mitsubishielectric l06cpu-p firmwareall versionsnvdUScpe:2.3:o:mitsubishielectric:l06cpu-p_firmware:*:*:*:*:*:*:*:*
mitsubishielectric l26cpu firmwareall versionsnvdUScpe:2.3:o:mitsubishielectric:l26cpu_firmware:*:*:*:*:*:*:*:*
mitsubishielectric l26cpu-bt firmwareall versionsnvdUScpe:2.3:o:mitsubishielectric:l26cpu-bt_firmware:*:*:*:*:*:*:*:*

showing 20 of 49

advisories (1)

Vendor and ecosystem advisories describing this.

ICSA-20-091-02Mitsubishi Electric MELSEC2020-03-31icsa · cisa_csaf_otUS
Successful exploitation of this vulnerability may render the device unresponsive.

also known as (3)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd cisa_csaf_ot nvd NVD CVE.org MITRE

published 2020-03-30modified 2026-06-17

related (9,616)

Related entries.

ID	severity	EPSS	exploitable	published
CVE-2026-28318US	—OT critical	43.7% (99th)	KEV	2026-06-04
SolarWinds Serv-U is susceptible to specially crafted POST requests that crash the Serv-U service without authentication using Content-Encoding: deflate. Mitigation steps are provi…
CVE-2026-45498US	high7.5OT critical	63.1% (99th)	KEV	2026-05-20
Microsoft Defender Denial of Service Vulnerability
CVE-2023-44487US	high7.5OT critical	100.0% (100th)	KEV	2023-10-10
The HTTP/2 protocol allows a denial of service (server resource consumption) because request cancellation can reset many streams quickly, as exploited in the wild in August through…
CVE-2023-38180US	—OT critical	14.1% (97th)	KEV	2023-08-08
.NET and Visual Studio Denial of Service Vulnerability
CVE-2021-44228US	critical10.0OT critical	100.0% (100th)	KEV	2021-12-10
Apache Log4j2 2.0-beta9 through 2.15.0 (excluding security releases 2.12.2, 2.12.3, and 2.3.1) JNDI features used in configuration, log messages, and parameters do not protect agai…

+9611 more

references (8)

External citations — patches, advisories, analysis.

scry

Attackers weaponise vulnerabilities like this against internet-exposed services. See what is exposed on your perimeter with a free passive scan.

Free scan