Vulnerability in Mitsubishi Electric Corporation Melsec-Q Series Q03udvcpu

CVE-2025-8531

Improper Handling of Length Parameter Inconsistency vulnerability in Mitsubishi Electric Corporation MELSEC-Q Series Q03UDVCPU, Q04UDVCPU, Q06UDVCPU, Q13UDVCPU, Q26UDVCPU, Q04UDPVCPU, Q06UDPVCPU, Q13UDPVCPU, and Q26UDPVCPU with the first 5 digits of serial No. "24082" to "27081" allows a remote attacker to cause an integer underflow by sending specially crafted packets to the affected product to stop Ethernet communication and the execution of control programs on the product, when the user authentication function is enabled. The user authentication function is enabled by default only when settings are configured by GX Works2, which complies with the Cybersecurity Law of the People's Republic of China, and is normally disabled.

EPSS: 0.010 (57.7th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 6.8 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:N/A:H.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2025-8531?
CVE-2025-8531 is a medium-severity vulnerability in Mitsubishi Electric Corporation Melsec-Q Series Q03udvcpu, classified under Improper Handling of Length Parameter Inconsistency. CVSS score: 6.8/10. Published 2025-09-19.
How severe is CVE-2025-8531?
Medium severity. CVSS v3 base score is 6.8 out of 10.