CVE-2026-14480

CVE-2026-14480 is a critical-severity vulnerability with a CVSS 3.x base score of 9.9. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-73.

Key facts

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.

Frequently asked questions

What is CVE-2026-14480?
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.
How severe is CVE-2026-14480?
CVE-2026-14480 has a CVSS 3.x base score of 9.9, rated critical severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2026-14480 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (37th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-14480?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2026-14480 published?
CVE-2026-14480 was published on 2026-07-10 and last updated on 2026-07-13.

References

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