Dalfox Server Mode has an Unauthenticated Arbitrary File Create/Append via `output` Option — CVE-2026-45089

Summary

## Summary When dalfox is run in REST API server mode, the `output`, `output-all`, and `debug` fields in `model.Options` are JSON-tagged and deserialized directly from the attacker's request body, then propagated unchanged through `dalfox.Initialize` into the scan engine's logging path. The logger opens the attacker-supplied path with `os.O_APPEND|os.O_CREATE|os.O_WRONLY` and writes scan log lines to it.…

Product

go: github.com/hahwul/dalfox/v2

What to do

General, cautious steps (verify details in the official source):

• Prioritize patching or mitigation immediately (treat as actively risky).
• Identify affected product versions in your inventory and verify whether you are impacted.
• Apply vendor patches/updates or recommended mitigations as soon as available.
• Read the official advisory for exact affected versions and remediation steps.

Official advisory

• Read the official source
• CVE Record
• NVD

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