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

> Authenticated users can inject JavaScript via Markdown rendering in Langflow Desktop, potentially stealing credentials from trusted sessions.

- **Severity:** Medium 6.4 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 30 Apr 2026
- **Updated:** 1 May 2026
- **Also known as:** GHSA-m357-46wc-mgw8

## 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 (Improper Neutralization of Special Elements used in an SQL Command)

## Which versions are affected by CVE-2026-3346?

It affects 1 product.


Products: 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.

## 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](https://insights.sbomify.com/CVE-2026-6543/): Authenticated Remote Code Execution Vulnerability in Langflow Code Validation Endpoint (high 8.8)
- [CVE-2026-4503](https://insights.sbomify.com/CVE-2026-4503/): Unauthenticated Insecure Direct Object Reference (IDOR) Vulnerability in Langflow Desktop Image Download Endpoint (high 7.5)
- [CVE-2026-3340](https://insights.sbomify.com/CVE-2026-3340/): Server-Side Request Forgery (SSRF) in Langflow URL Component (medium 6.5)
- [CVE-2026-3345](https://insights.sbomify.com/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](https://insights.sbomify.com/CVE-2026-4502/): Arbitrary File Write and Remote Code Execution Vulnerability in Langflow v2 API (medium 6.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-3346 and fix it if it is affected.

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

Affected product: IBM Langflow Desktop. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-3346/ (Markdown: https://insights.sbomify.com/CVE-2026-3346/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-3346
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-3346
- OSV: https://osv.dev/vulnerability/CVE-2026-3346

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-3346/
Summaries are generated and may contain mistakes; the official description above is the record.