GHSA-j8g8-j7fc-43v6: Flowise has Arbitrary File Upload via MIME Spoofing
- Identifiers
- CVE-2026-30821GHSA-j8g8-j7fc-43v6
- Published
- Record updated
- Affected
- flowise <= 3.0.12
- Fixed in
- 3.0.13
- released February 3, 2026, 31 days before disclosure
- Known exploitation
- Not listed in the CISA Known Exploited Vulnerabilities catalog at the last check.
- EPSS
- 16.7%
Summary
The `/api/v1/attachments/:chatflowId/:chatId` endpoint in Flowise is listed in `WHITELIST_URLS`, so it accepts uploads without authentication. The server checks uploads against the MIME types in `chatbotConfig.fullFileUpload.allowedUploadFileTypes` but trusts the client-supplied `Content-Type` header without checking file contents or extension. An attacker can upload scripts or other arbitrary files by declaring a permitted type such as `application/pdf`, and the files persist in backend storage. Chained with static hosting or file retrieval, this can lead to Stored XSS, malicious file hosting, or Remote Code Execution.
Mitigation
The source does not state a fix yet. Check the original advisory for updates.
Affected packages in the Exposure Registry
Matched by package name and ecosystem. Each entry shows whether the package delegates to a language model and how many tracked packages depend on it.
- flowisenpmLLM dependency since 2024-03-12
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