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Fencer Vulns
high 7.5

CVE-2021-27432 json

OPC Foundation UA .NET Standard versions prior to 1.4.365.48 and OPC UA .NET Legacy are vulnerable to an uncontrolled recursion, which may…

published 2021-05-20 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-14186

cvss
7.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
1.9%
EPSS 1.9% chance of exploitation in 30 days, percentile 80%
public exploits
0
none known

Summary

OPC Foundation UA .NET Standard versions prior to 1.4.365.48 and OPC UA .NET Legacy are vulnerable to an uncontrolled recursion, which may allow an attacker to trigger a stack overflow.

Patch / fix

  • opcfoundation ua_.net_standard_stack 1.4.365.48

Vendor advisories

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

cisa ICSA-21-294-03 updated cvss 7.5

ICONICS GENESIS64 and Mitsubishi Electric MC Works64 OPC UA

  • ICONICS, Mitsubishi Electric AnalytiX <= 10.97 ICONICS, Mitsubishi Electric GENESIS64 <= 10.97 ICONICS, Mitsubishi Electric Hyper Historian <= 10.97 ICONICS, Mitsubishi Electric MC Works64 <= 4.04E ICONICS, Mitsubishi Electric MobileHMI <= 10.97
    affected: mitigation “Place control system networks and devices behind firewalls to isolate them from the business network.” mitsubishielectric.com

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

cisa ICSA-21-133-03 updated cvss 7.5

OPC Foundation UA Products Built with .NET Framework

  • OPC Foundation OPC UA .NET Standard < 1.4.365.48
    affected: vendor fix github.com

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

1.95% chance of exploitation in the next 30 days, higher than 80% 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

  • n/a OPC Foundation OPC UA .NET Standard and OPC UA .NET Legacy

Classification

Weakness

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.