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OpenAdvisories
High · 8.2 CVE-2026-45089 EUVD-2026-32614GHSA-8hf9-3q64-q2qfGO-2026-5257

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

Published May 27, 2026 · Updated May 27, 2026 · Assigned by GitHub_M

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.

Affected products

VendorProductAffectedFixed
hahwul dalfox < 2.13.0 —

Fixed in Linux distributions

Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.

ReleasePackageFixed inAdvisory
openSUSE Leap 16.0 govulncheck-vulndb 0.0.20260723T184607-160000.1.1 openSUSE-SU-2026:21483-1

Affected packages

EcosystemPackageAffectedFixedRecord
Go github.com/hahwul/dalfox all versions — GO-2026-5257
Go github.com/hahwul/dalfox/v2 < 2.13.0 2.13.0 GHSA-8hf9-3q64-q2qf

Advisories 1

References