No exploitation reportedFix available

CVE-2020-5652

Q: Is CVE-2020-5652 actively exploited?

Active exploitation of CVE-2020-5652 has not been confirmed. Its EPSS score was 3.6% on 2026-10-23, the estimated probability of exploitation in the next 30 days.

Q: What is the CVSS score for CVE-2020-5652?

CVE-2020-5652 has a CVSS v3 base score of 7.5 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

No exploitation reported by the sources we read.

Published2020-11-02
WeaknessCWE-400

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

Uncontrolled resource consumption vulnerability in Ethernet Port on MELSEC iQ-R, Q and L series CPU modules (R 00/01/02 CPU firmware versions '20' and earlier, R 04/08/16/32/120 (EN) CPU firmware versions '52' and earlier, R 08/16/32/120 SFCPU firmware versions '22' and earlier, R 08/16/32/120 PCPU all versions, R 08/16/32/120 PSFCPU all versions, R 16/32/64 MTCPU all versions, Q03 UDECPU, Q 04/06/10/13/20/26/50/100 UDEHCPU serial number '22081' and earlier , Q 03/04/06/13/26 UDVCPU serial number '22031' and earlier, Q 04/06/13/26 UDPVCPU serial number '22031' and earlier, Q 172/173 DCPU all versions, Q 172/173 DSCPU all versions, Q 170 MCPU all versions, Q 170 MSCPU all versions, L 02/06/26 CPU (-P) and L 26 CPU - (P) BT all versions) allows a remote unauthenticated attacker to stop the Ethernet communication functions of the products via a specially crafted packet, which may lead to a denial of service (DoS) condition .

Timeline

dates in UTC

2020-11-0221:15CVE publishedNVD

Observed activity

isMalicious corpus · updated 2026-10-23 21:37 UTC

Indicators tagged with this CVE, per day0 indicators over 7 days

Block these indicators

Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2020-5652?format=txt
CSV export: https://api.ismalicious.com/edl/cve/CVE-2020-5652?format=csv
TAXII collection of exploited CVEs
The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD

Mitsubishielectric melsec iq-r00cpu firmwareversion to verify

Branch	Affected	Fixed in	Source
20.x	= 20	no fix published	NVD

Mitsubishielectric melsec iq-r01cpu firmwareversion to verify

Branch	Affected	Fixed in	Source
20.x	= 20	no fix published	NVD

Mitsubishielectric melsec iq-r02cpu firmwareversion to verify

Branch	Affected	Fixed in	Source
20.x	= 20	no fix published	NVD

48 more products in the sources.

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Distribution builds and vendor advisories

Packages from OSV.dev and products from the vendors' CSAF advisories.

version not verifiedVersions not verified: read as OSV.dev and the vendors publish them, not checked against each vendor's release list.

Vendor advisories

ICSA-20-303-01 CISA52 known affected
Mitsubishi Electric MELSEC iQ-R, Q, and L Series (Update E)
Mitsubishi Electric MELSEC iQ-R R00 CPU firmware: <=20 · Mitsubishi Electric MELSEC iQ-R R01 CPU firmware: <=20 · Mitsubishi Electric MELSEC iQ-R R02 CPU firmware: <=20 · +49 more

Full record on NVD

Fix

Vendor fix CISA ICSA-20-303-01 · 1 productMELSEC iQ-R R00 CPU firmware: Refer to "Appendix 2 Firmware Update Function" in the MELSEC iQ-R Module Configuration Manual
Vendor fix CISA ICSA-20-303-01 · 1 productMELSEC iQ-R R01 CPU firmware: Refer to "Appendix 2 Firmware Update Function" in the MELSEC iQ-R Module Configuration Manual
Vendor fix CISA ICSA-20-303-01 · 1 productMELSEC iQ-R R02 CPU firmware: Refer to "Appendix 2 Firmware Update Function" in the MELSEC iQ-R Module Configuration Manual
Vendor fix CISA ICSA-20-303-01 · 1 productMELSEC iQ-R R04 (EN) CPU firmware: Refer to "Appendix 2 Firmware Update Function" in the MELSEC iQ-R Module Configuration Manual
Vendor fix CISA ICSA-20-303-01 · 1 productMELSEC iQ-R R08 (EN) CPU firmware: Refer to "Appendix 2 Firmware Update Function" in the MELSEC iQ-R Module Configuration Manual
Vendor fix CISA ICSA-20-303-01 · 1 productMELSEC iQ-R R16 (EN) CPU firmware: Refer to "Appendix 2 Firmware Update Function" in the MELSEC iQ-R Module Configuration Manual

Advisories and patches

www.mitsubishielectric.co.jpVendor Advisory
www.mitsubishielectric.comVendor Advisory

Detection

Nuclei template: none so far
Exploit-DB: no entry
Proof-of-concept repositories: none listed

Sources

NVDCVSS 3.17.5read 2026-10-23
NVDCVSS 2.05read 2026-10-23
NVDweakness (CWE)CWE-400read 2026-10-23
FIRST EPSSEPSS score3.6 %2026-10-23

Technical details

CVSS v3 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Published: 2020-11-02
Last Modified: 2026-06-17
NVD status: Modified

Frequently asked questions

What is CVE-2020-5652?

Is CVE-2020-5652 actively exploited?

Active exploitation of CVE-2020-5652 has not been confirmed. Its EPSS score was 3.6% on 2026-10-23, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2020-5652?

CVE-2020-5652 has a CVSS v3 base score of 7.5 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

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