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OpenPLC v3

CRITICAL
CVSS 9.9
Date 2026-07-09T06:00:00+00:00
Source cisa-csaf
Published by CISA

// Description

Successful exploitation of this vulnerability could allow an authenticated attacker to write arbitrary files to the filesystem and escalate this into arbitrary native code execution through the normal OpenPLC program compilation process, potentially resulting in code execution as the OpenPLC runtime user.

// Vulnerabilities (1)

CVE ID CVSS Score Severity Description
CVE-2026-14480 9.9 critical
OpenPLC Runtime v3 contains an authenticated arbitrary file write vulnerability in the legacy web UI program‑upload workflow. The application stores an attacker‑supplied filename (prog_file) directly into the Programs.File database field and later uses this value as the destination path for an uploaded file without validating or restricting the path. Because Python os.path.join() honors attacker‑controlled absolute paths, an authenticated user can write arbitrary files anywhere writable by the OpenPLC webserver process. In the default build pipeline, all C++ source files within the OpenPLC runtime core directory are automatically compiled into the executable runtime binary. By writing a malicious .cpp file into this directory, an authenticated attacker can escalate the arbitrary file write into arbitrary native code execution when the operator triggers a normal program compilation and runtime start.

// Affected Products (1)

Vendor Product Asset Type Purdue Level Firmware
OpenPLC Unknown plc
L1
v3

// Remediations (1)

Patch: OpenPLC recommends users upgrade to OpenPLC v4 as OpenPLC v3 is end-of-life and is no longer receivi
OpenPLC recommends users upgrade to OpenPLC v4 as OpenPLC v3 is end-of-life and is no longer receiving patches, bug fixes, or security updates.

// References