What is CVE-2021-20610?

CVE-2021-20610 is a high-severity vulnerability in Mitsubishi Melipc Mi5122-Vw, classified under Improper Handling of Length Parameter Inconsistency. CVSS score: 7.5/10. Published 2021-12-01.

How severe is CVE-2021-20610?

High severity. CVSS v3 base score is 7.5 out of 10.

Is CVE-2021-20610 known to be exploited?

1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

Vulnerability in Mitsubishi Melipc Mi5122-Vw

CVE-2021-20610

Improper Handling of Length Parameter Inconsistency vulnerability in Mitsubishi Electric MELSEC iQ-R Series R00/01/02CPU, MELSEC iQ-R Series R04/08/16/32/120(EN)CPU, MELSEC iQ-R Series R08/16/32/120SFCPU, MELSEC iQ-R Series R08/16/32/120PCPU, MELSEC iQ-R Series R08/16/32/120PSFCPU, MELSEC iQ-R Series R16/32/64MTCPU, MELSEC iQ-R Series R12CCPU-V, MELSEC Q Series Q03UDECPU, MELSEC Q Series Q04/06/10/13/20/26/50/100UDEHCPU, MELSEC Q Series Q03/04/06/13/26UDVCPU, MELSEC Q Series Q04/06/13/26UDPVCPU, MELSEC Q Series Q12DCCPU-V, MELSEC Q Series Q24DHCCPU-V(G), MELSEC Q Series Q24/26DHCCPU-LS, MELSEC Q Series MR-MQ100, MELSEC Q Series Q172/173DCPU-S1, MELSEC Q Series Q172/173DSCPU, MELSEC Q Series Q170MCPU, MELSEC Q Series Q170MSCPU(-S1), MELSEC L Series L02/06/26CPU(-P), MELSEC L Series L26CPU-(P)BT and MELIPC Series MI5122-VW allows a remote unauthenticated attacker to cause a denial-of-service (DoS) condition by sending specially crafted packets. System reset is required for recovery.

Published 2021-12-01 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.033 (88.0th percentile), scored 2026-09-30.

Low probability of exploitation in the next 30 days, but still tracked. 88th percentile — 88.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.031 · newest: 0.033 · change: +0.002

Affected products

Weakness classification (CWE)

CWE-130 — Improper Handling of Length Parameter Inconsistency

Public proof-of-concept exploits

fkie-cad/nvd-json-data-feeds

References

www.mitsubishielectric.com/en/psirt/vulnerability/pdf/2021-019_en.pdf (vendor-advisory, Vendor Advisory)
jvn.jp/vu/JVNVU94434051/index.html (Third Party Advisory, government-resource)
us-cert.cisa.gov/ics/advisories/icsa-21-334-02 (US Government Resource, Third Party Advisory, government-resource)

Frequently asked questions

What is CVE-2021-20610?: CVE-2021-20610 is a high-severity vulnerability in Mitsubishi Melipc Mi5122-Vw, classified under Improper Handling of Length Parameter Inconsistency. CVSS score: 7.5/10. Published 2021-12-01.
How severe is CVE-2021-20610?: High severity. CVSS v3 base score is 7.5 out of 10.
Is CVE-2021-20610 known to be exploited?: 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.