CVE-2026-71268
CRITICALCVE-2026-71268 is a critical-severity (CVSS 9.9) Path Traversal vulnerability. O3 Security confirms whether CVE-2026-71268 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
OpenPLC Runtime v3's compile_program() function (webserver/openplc.py) parses `(*FILE:path content*)` directives from uploaded Structured Text (.st) program files and writes the referenced…
Description
OpenPLC Runtime v3's compile_program() function (webserver/openplc.py) parses (*FILE:path content*) directives from uploaded Structured Text (.st) program files and writes the referenced content to os.path.join('./core', file_path) with no validation that file_path stays within the ./core directory. A crafted .st file containing a directive such as (*FILE:../../../etc/cron.d/x * * * * root <command>*) writes attacker-controlled content to an arbitrary filesystem path, enabling remote code execution (e.g. via cron or SSH authorized_keys). 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. OpenPLC additionally ships with hardcoded default credentials (openplc:openplc), lowering the practical bar for exploitation.
Detection & mitigation playbook
VulnerabilityDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for the affected component. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Remediation status
No patched version of the affected component has shipped for CVE-2026-71268 yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.
Mitigate without a patch
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2026-71268 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2026-71268. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-71268 in your dependencies?
O3 detects CVE-2026-71268 across dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.