CVE-2026-41269 Flowise: File Upload Validation Bypass in createAttachment

What is CVE-2026-41269?

CVE-2026-41269 is a high-severity vulnerability in Flowiseai Flowise, published on 23 Apr 2026. Any signed-in user can exploit it over the network, with no action from the victim.

Official description

Flowise is a drag & drop user interface to build a customized large language model flow. Prior to 3.1.0, the Chatflow configuration file upload settings can be modified to allow the application/javascript MIME type. This lets an attacker upload .js files even though the frontend doesn’t normally allow JavaScript uploads. This enables attackers to persistently store malicious Node.js web shells on the server, potentially leading to Remote Code Execution (RCE). This vulnerability is fixed in 3.1.0.

Weakness: CWE-434

Which versions are affected by CVE-2026-41269?

2 open source packages ship an affected version, including flowise. It affects 1 product.

Products include Flowiseai Flowise.

How do I fix CVE-2026-41269?

Upgrade flowise to 3.1.0 or later.

Is CVE-2026-41269 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-41269 exists.

Other vulnerabilities in Flowiseai Flowise

• CVE-2025-71338 Flowise through 2.2.7 - Arbitrary File Write to Remote Code Execution via document-store API Critical 10.0
• CVE-2026-40933 Flowise: Authenticated RCE Via MCP Adapters Critical 10.0
• CVE-2025-61913 Flowise is vulnerable to arbitrary file read, arbitrary file write Critical 10.0
• CVE-2025-59528 Flowise has Remote Code Execution vulnerability Critical 10.0
• CVE-2026-52098 Code injection in n/a Critical 9.8

All Flowiseai Flowise vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as GHSA-rh7v-6w34-w2rr.