No exploitation reportedFix available

CVE-2020-5668

No exploitation reported by the sources we read.

Published2020-11-20
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 MELSEC iQ-R Series modules (R00/01/02CPU firmware version '19' and earlier, R04/08/16/32/120 (EN) CPU firmware version '51' and earlier, R08/16/32/120SFCPU firmware version '22' and earlier, R08/16/32/120PCPU firmware version '25' and earlier, R08/16/32/120PSFCPU firmware version '06' and earlier, RJ71EN71 firmware version '47' and earlier, RJ71GF11-T2 firmware version '47' and earlier, RJ72GF15-T2 firmware version '07' and earlier, RJ71GP21-SX firmware version '47' and earlier, RJ71GP21S-SX firmware version '47' and earlier, and RJ71GN11-T2 firmware version '11' and earlier) allows a remote unauthenticated attacker to cause an error in a CPU unit and cause a denial-of-service (DoS) condition in execution of the program and its communication, or to cause a denial-of-service (DoS) condition in communication via the unit by receiving a specially crafted SLMP packet

Timeline

dates in UTC

2020-11-2004:15CVE publishedNVD

Observed activity

isMalicious corpus · updated 2026-10-23 18:48 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-2020-5668?format=txt
CSV export: https://api.ismalicious.com/edl/cve/CVE-2020-5668?format=csv
TAXII collection of exploited CVEs
The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD

Mitsubishielectric r00cpu firmwareversion to verify

Branch	Affected	Fixed in	Source
19.x	≤ 19	no fix published	NVD

Mitsubishielectric r01cpu firmwareversion to verify

Branch	Affected	Fixed in	Source
19.x	≤ 19	no fix published	NVD

Mitsubishielectric r02cpu firmwareversion to verify

Branch	Affected	Fixed in	Source
19.x	≤ 19	no fix published	NVD

25 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-20-324-05 CISA12 known affected
Mitsubishi Electric MELSEC iQ-R Series (Update C)
RJ71GF11-T2: firmware Versions 47 and earlier · RJ71C24(-R2/R4): all versions · RJ71GP21S-SX: firmware Versions 47 and earlier · +9 more

Full record on NVD

Fix

Vendor fix CISA ICSA-20-324-05 · 12 productsMitsubishi Electric has issued the following iQ-R Series firmware versions to address this issue: R08/16/32/120PCPU: firmware Versions 26 or later
Mitigation from the vendor CISA ICSA-20-324-05 · 12 productsMitsubishi Electric has issued the following iQ-R Series firmware versions to address this issue: R00/01/02CPU: firmware Versions 20 or later
Mitigation from the vendor CISA ICSA-20-324-05 · 12 productsMitsubishi Electric has issued the following iQ-R Series firmware versions to address this issue: R04/08/16/32/120 (EN) CPU: firmware Versions 52 or later
Mitigation from the vendor CISA ICSA-20-324-05 · 12 productsMitsubishi Electric has issued the following iQ-R Series firmware versions to address this issue: R08/16/32/120SFCPU: firmware Versions 23 or later
Mitigation from the vendor CISA ICSA-20-324-05 · 12 productsMitsubishi Electric has issued the following iQ-R Series firmware versions to address this issue: R08/16/32/120PSFCPU: firmware Versions 07 or later
Mitigation from the vendor CISA ICSA-20-324-05 · 12 productsMitsubishi Electric has issued the following iQ-R Series firmware versions to address this issue: RJ71EN71: firmware Versions 48 or later

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 2.07.8read 2026-10-23
NVDweakness (CWE)CWE-400read 2026-10-23
FIRST EPSSEPSS score4.9 %2026-10-22

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: 2020-11-20
Last Modified: 2026-06-17
NVD status: Modified

Frequently asked questions

What is CVE-2020-5668?

Is CVE-2020-5668 actively exploited?

Active exploitation of CVE-2020-5668 has not been confirmed. Its EPSS score was 4.9% on 2026-10-22, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2020-5668?

CVE-2020-5668 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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