How severe is CVE-2020-5668?

CVE-2020-5668 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2020-5668 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 5% (91st percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-5668?

CVE-2020-5668 primarily affects Mitsubishielectric R00cpu Firmware. In total, 28 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2020-5668?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2020-5668 published?

CVE-2020-5668 was published on 2020-11-20 and last updated on 2026-06-17.

CVE-2020-5668

CVE-2020-5668 is a high-severity vulnerability in Mitsubishielectric R00cpu Firmware with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-400.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v2: 7.8
EPSS exploit prediction: 5% (91st percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-400
Affected product: Mitsubishielectric R00cpu Firmware
Published: 2020-11-20
Last modified: 2026-06-17

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

Frequently asked questions

What is CVE-2020-5668?: 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
How severe is CVE-2020-5668?: CVE-2020-5668 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2020-5668 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 5% (91st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-5668?: CVE-2020-5668 primarily affects Mitsubishielectric R00cpu Firmware. In total, 28 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2020-5668?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2020-5668 published?: CVE-2020-5668 was published on 2020-11-20 and last updated on 2026-06-17.

References

Affected products (28)

cpe:2.3:o:mitsubishielectric:r00cpu_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:mitsubishielectric:r01cpu_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:mitsubishielectric:r02cpu_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:mitsubishielectric:r04cpu_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:mitsubishielectric:r08cpu_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:mitsubishielectric:r16cpu_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:mitsubishielectric:r32cpu_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:mitsubishielectric:r120cpu_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:mitsubishielectric:r08sfcpu_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:mitsubishielectric:r16sfcpu_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:mitsubishielectric:r32sfcpu_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:mitsubishielectric:r120sfcpu_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:mitsubishielectric:r08pcpu_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:mitsubishielectric:r16pcpu_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:mitsubishielectric:r32pcpu_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:mitsubishielectric:r120pcpu_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:mitsubishielectric:r08psfcpu_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:mitsubishielectric:r16psfcpu_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:mitsubishielectric:r32psfcpu_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:mitsubishielectric:r120psfcpu_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:mitsubishielectric:rj71en71_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:mitsubishielectric:rj71gf11-t2_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:mitsubishielectric:rj72gf15-t2_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:mitsubishielectric:rj71gp21-sx_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:mitsubishielectric:rj71gp21s-sx_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:mitsubishielectric:rj71c24-r2_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:mitsubishielectric:rj71c24-r4_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:mitsubishielectric:rj71gn11-t2_firmware:*:*:*:*:*:*:*:*

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