What is CVE-2021-40873?

CVE-2021-40873 is a high-severity vulnerability in Softing Datafeed Opc Suite, classified under Double Free. CVSS score: 7.5/10. Published 2021-11-10.

How severe is CVE-2021-40873?

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

Double Free in Softing Datafeed Opc Suite

CVE-2021-40873

An issue was discovered in Softing Industrial Automation OPC UA C++ SDK before 5.66, and uaToolkit Embedded before 1.40. Remote attackers to cause a denial of service (DoS) by sending crafted messages to a client or server. The server process may crash unexpectedly because of a double free, and must be restarted.

Vulnerability class: Double Free

Published 2021-11-10 · 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: 0.013 (70.6th percentile), scored 2026-10-31.

Low probability of exploitation in the next 30 days, but still tracked. 71st percentile — 70.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.013 · newest: 0.013 · change: 0.000

Affected products

Weakness classification (CWE)

CWE-415 — Double Free

References

industrial.softing.com/ (Vendor Advisory)
industrial.softing.com/fileadmin/sof-files/pdf/ia/support/Security_Bulletin_CVE… (Vendor Advisory)

Frequently asked questions

What is CVE-2021-40873?: CVE-2021-40873 is a high-severity vulnerability in Softing Datafeed Opc Suite, classified under Double Free. CVSS score: 7.5/10. Published 2021-11-10.
How severe is CVE-2021-40873?: High severity. CVSS v3 base score is 7.5 out of 10.