Vulnerability Description
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.
CVSS Score
CRITICAL
Related Weaknesses (CWE)
References
- https://github.com/cisagov/CSAF/blob/develop/csaf_files/OT/white/2026/icsa-26-19
- https://www.cisa.gov/news-events/ics-advisories/icsa-26-190-01
FAQ
What is CVE-2026-14480?
CVE-2026-14480 is a vulnerability with a CVSS score of 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) directl...
How severe is CVE-2026-14480?
CVE-2026-14480 has been rated CRITICAL with a CVSS base score of 9.9/10. This is considered a critical vulnerability requiring immediate attention.
Is there a patch for CVE-2026-14480?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.