CVE-2025-54811: OpenPLC_V3

Severity: high (CVSS 7.1 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-10-01 · updated 2026-10-19
Weakness: CWE-758

Description

OpenPLC_V3 has a vulnerability in the enipThread function that occurs due to the lack of a return value. This leads to a crash when the server loop ends and execution hits an illegal ud2 instruction. This issue can be triggered remotely without authentication by starting the same server multiple times or if the server exits unexpectedly. The vulnerability allows an attacker to cause a Denial of Service (DoS) against the PLC runtime, stopping any PC started remotely without authentication. This results in the PLC process crashing and halting all automation or control logic managed by OpenPLC.

Affected products

OpenPLC_v3: before pull request #292 — fixed in pull request #292

How to fix

Upgrade to a fixed version: OpenPLC_v3 pull request #292. Check the vendor advisory for mitigations.

References

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