Dalfox is a powerful open-source XSS scanner and utility focused on automation. Prior to 2.13.0, 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. Critically, this file write block lives outside the IsLibrary guard in DalLog, so it executes even in server/library mode where file output was never intended to operate. Because no API key is required in the default configuration, an unauthenticated network caller can create or append to any file writable by the dalfox process on the host filesystem. This vulnerability is fixed in 2.13.0.

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Advisories
Source ID Title
Github GHSA Github GHSA GHSA-8hf9-3q64-q2qf Dalfox Server Mode has an Unauthenticated Arbitrary File Create/Append via `output` Option
Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Wed, 27 May 2026 18:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Wed, 27 May 2026 17:45:00 +0000

Type Values Removed Values Added
Description Dalfox is a powerful open-source XSS scanner and utility focused on automation. Prior to 2.13.0, 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. Critically, this file write block lives outside the IsLibrary guard in DalLog, so it executes even in server/library mode where file output was never intended to operate. Because no API key is required in the default configuration, an unauthenticated network caller can create or append to any file writable by the dalfox process on the host filesystem. This vulnerability is fixed in 2.13.0.
Title Dalfox: Unauthenticated Arbitrary File Create/Append via `output` Option in Dalfox Server Mode
Weaknesses CWE-306
CWE-434
CWE-73
References
Metrics cvssV3_1

{'score': 8.2, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:L'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-05-27T17:59:46.662Z

Reserved: 2026-05-08T19:27:26.697Z

Link: CVE-2026-45089

cve-icon Vulnrichment

Updated: 2026-05-27T17:59:43.738Z

cve-icon NVD

Status : Deferred

Published: 2026-05-27T18:16:24.863

Modified: 2026-05-27T19:49:48.143

Link: CVE-2026-45089

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses