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Fencer Vulns
high 7.5

CVE-2020-5652 json

Uncontrolled resource consumption vulnerability in Ethernet Port on MELSEC iQ-R, Q and L series CPU modules (R 00/01/02 CPU firmware versio…

published 2020-10-30 6 y ago modified 2026-06-17 4 mo ago also EUVD-2020-26813

cvss
7.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
3.6%
EPSS 3.6% chance of exploitation in 30 days, percentile 89%
public exploits
0
none known

Summary

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 .

Vendor advisories

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

cisa ICSA-20-303-01 updated cvss 7.5

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 Mitsubishi Electric MELSEC iQ-R R04 (EN) CPU firmware <=52 Mitsubishi Electric MELSEC iQ-R R08 (EN) CPU firmware <=52 Mitsubishi Electric MELSEC iQ-R R08 PCPU firmware <=24
    +17 more products
    Mitsubishi Electric MELSEC iQ-R R08 PSFCPU firmware <=06 Mitsubishi Electric MELSEC iQ-R R08 SFCPU firmware <=22 Mitsubishi Electric MELSEC iQ-R R16 (EN) CPU firmware <=52 Mitsubishi Electric MELSEC iQ-R R16 MTCPU operating system software <=21 Mitsubishi Electric MELSEC iQ-R R16 PCPU firmware <=24 Mitsubishi Electric MELSEC iQ-R R16 PSFCPU firmware <=06 Mitsubishi Electric MELSEC iQ-R R16 SFCPU firmware <=22 Mitsubishi Electric MELSEC iQ-R R32 (EN) CPU firmware <=52 Mitsubishi Electric MELSEC iQ-R R32 MTCPU operating system software <=21 Mitsubishi Electric MELSEC iQ-R R32 PCPU firmware <=24 Mitsubishi Electric MELSEC iQ-R R32 PSFCPU firmware <=06 Mitsubishi Electric MELSEC iQ-R R32 SFCPU firmware <=22 Mitsubishi Electric MELSEC iQ-R R64 MTCPU operating system software <=21 Mitsubishi Electric MELSEC iQ-R R120 (EN) CPU firmware <=52 Mitsubishi Electric MELSEC iQ-R R120 PCPU firmware <=24 Mitsubishi Electric MELSEC iQ-R R120 PSFCPU firmware <=06 Mitsubishi Electric MELSEC iQ-R R120 SFCPU firmware <=22
    affected: vendor fix, mitigation “Mitsubishi Electric released the fixed version of the product. Refer to the list below to check if the version of your product is updatable and take the measures described after the list:” mitsubishielectric.com
  • Mitsubishi Electric MELSEC L L02 CPU (-P) <=the_first_5_digits_of_serial_number_23121 Mitsubishi Electric MELSEC L L06 CPU (-P) <=the_first_5_digits_of_serial_number_23121
    affected: mitigation “Mitsubishi Electric released the fixed version of the product. Refer to the list below to check if the version of your product is updatable and take the measures described after the list:” mitsubishielectric.com
  • Mitsubishi Electric MELSEC L L26 CPU - (P) BT <=the_first_5_digits_of_serial_number_23121
    affected: vendor fix, mitigation “Mitsubishi Electric released the fixed version of the product. Refer to the list below to check if the version of your product is updatable and take the measures described after the list:” mitsubishielectric.com
  • Mitsubishi Electric MELSEC L L26 CPU (-P) <=the_first_5_digits_of_serial_number_23121
    affected: mitigation “Mitsubishi Electric released the fixed version of the product. Refer to the list below to check if the version of your product is updatable and take the measures described after the list:” mitsubishielectric.com
  • Mitsubishi Electric MELSEC Q MR-MQ100 operating system software <=E Mitsubishi Electric MELSEC Q Q03 UDECPU <=the_first_5_digits_of_serial_number_22081 Mitsubishi Electric MELSEC Q Q03 UDVCPU <=the_first_5_digits_of_serial_number_22031 Mitsubishi Electric MELSEC Q Q04 UDEHCPU <=the_first_5_digits_of_serial_number_22081 Mitsubishi Electric MELSEC Q Q04 UDPVCPU <=the_first_5_digits_of_serial_number_22031 Mitsubishi Electric MELSEC Q Q04 UDVCPU <=the_first_5_digits_of_serial_number_22031
    +7 more products
    Mitsubishi Electric MELSEC Q Q06 UDEHCPU <=the_first_5_digits_of_serial_number_22081 Mitsubishi Electric MELSEC Q Q06 UDPVCPU <=the_first_5_digits_of_serial_number_22031 Mitsubishi Electric MELSEC Q Q06 UDVCPU <=the_first_5_digits_of_serial_number_22031 Mitsubishi Electric MELSEC Q Q10 UDEHCPU <=the_first_5_digits_of_serial_number_22081 Mitsubishi Electric MELSEC Q Q13 UDEHCPU <=the_first_5_digits_of_serial_number_22081 Mitsubishi Electric MELSEC Q Q13 UDPVCPU <=the_first_5_digits_of_serial_number_22031 Mitsubishi Electric MELSEC Q Q13 UDVCPU <=the_first_5_digits_of_serial_number_22031
    affected: vendor fix, mitigation “Mitsubishi Electric released the fixed version of the product. Refer to the list below to check if the version of your product is updatable and take the measures described after the list:” mitsubishielectric.com

12 more affected in the full advisory

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

3.57% chance of exploitation in the next 30 days, higher than 89% 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 MELSEC iQ-R, Q and L series

Classification

Weakness
  • CWE-400 Uncontrolled Resource Consumption

References

Sources

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.