CVE-2026-3346 Stored Cross-Site Scripting (XSS) in Langflow Markdown Rendering via rehypeRaw

What is CVE-2026-3346?

CVE-2026-3346 is a medium-severity cross-site scripting vulnerability in IBM Langflow Desktop, published on 30 Apr 2026. Any signed-in user can exploit it over the network, with no action from the victim.

Official description

IBM Langflow Desktop 1.6.0 through 1.8.4 Lanflow is vulnerable to stored cross-site scripting. This vulnerability allows an authenticated user to embed arbitrary JavaScript code in the Web UI thus altering the intended functionality potentially leading to credentials disclosure within a trusted session.

Weakness: CWE-89

Which versions are affected by CVE-2026-3346?

It affects 1 product.

Products include Langflow Langflow Desktop.

How do I fix CVE-2026-3346?

No fix has been published for CVE-2026-3346 yet. Limit exposure of the affected software until one is available.

Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.

Is CVE-2026-3346 being exploited?

There is no known exploitation of CVE-2026-3346 in the wild and no public exploit code.

Other vulnerabilities in IBM Langflow Desktop

• CVE-2026-6543 Authenticated Remote Code Execution Vulnerability in Langflow Code Validation Endpoint High 8.8
• CVE-2026-4503 Unauthenticated Insecure Direct Object Reference (IDOR) Vulnerability in Langflow Desktop Image Download Endpoint High 7.5
• CVE-2026-3340 Server-Side Request Forgery (SSRF) in Langflow URL Component Medium 6.5
• CVE-2026-3345 Path Traversal and Arbitrary File Write Vulnerability in IBM Langflow Desktop API v2 File Upload Endpoint Medium 6.5
• CVE-2026-4502 Arbitrary File Write and Remote Code Execution Vulnerability in Langflow v2 API Medium 6.5

Sources

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

Also known as GHSA-m357-46wc-mgw8.