# CVE-2026-71268: OpenPLC Runtime v3 Path Traversal in Structured Text FILE Directive Leading to Arbitrary File Write

> Attackers can write arbitrary files via path traversal in Structured Text directives, potentially leading to code execution on OpenPLC Runtime servers.

- **Severity:** Critical 9.9 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 5 Aug 2026
- **Updated:** 10 Aug 2026
- **Also known as:** GHSA-qprq-675r-82h6

## What is CVE-2026-71268?

CVE-2026-71268 is a critical path traversal vulnerability in thiagoralves OpenPLC_v3, published on 5 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

OpenPLC Runtime v3's compile_program function (webserver/openplc.py) parses directives from uploaded Structured Text (.st) program files and writes the referenced content to with no validation that file_path stays within the ./core directory. A path-validation function, validate_file_path, exists elsewhere in the codebase (webserver/credentials.py) but is never invoked from compile_program, leaving the sink unprotected.

Weakness: CWE-22 (Improper Limitation of a Pathname to a Restricted Directory)

## Which versions are affected by CVE-2026-71268?


## How do I fix CVE-2026-71268?

No fix has been published for CVE-2026-71268 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-71268 being exploited?

There is no known exploitation of CVE-2026-71268 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-71268 and fix it if it is affected.

What it is: CVE-2026-71268 is a critical path traversal vulnerability in thiagoralves OpenPLC_v3, published on 5 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-71268 in the wild and no public exploit code.

Affected product: thiagoralves OpenPLC_v3. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-71268/ (Markdown: https://insights.sbomify.com/CVE-2026-71268/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-71268
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-71268
- OSV: https://osv.dev/vulnerability/CVE-2026-71268

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-71268/
Summaries are generated and may contain mistakes; the official description above is the record.