CVE-2026-45089

HIGH

Dalfox: Unauthenticated Arbitrary File Create/Append via `output` Option in Dalfox Server Mode

Title source: cna
STIX 2.1

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.

References (2)

Core 2
Core References
X_Refsource_Misc x_refsource_misc
https://github.com/hahwul/dalfox/releases/tag/v2.13.0

Scores

CVSS v3 8.2
EPSS 0.0024
EPSS Percentile 15.2%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:L

CISA SSVC

Vulnrichment
Exploitation poc
Automatable yes
Technical Impact partial

Details

CWE
CWE-306 CWE-434 CWE-73
Status published
Products (2)
hahwul/dalfox 0 - 2.13.0Go
hahwul/dalfox < 2.13.0
Published May 27, 2026
Tracked Since May 27, 2026