# CVE-2026-8447: Cross-site scripting in Langflow OSS

> Attackers can inject malicious scripts via unsanitized Markdown in the Playground chat interface, potentially executing code or bypassing security controls.

- **Severity:** Medium 6.1 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 4 Sep 2026
- **Updated:** 4 Sep 2026
- **Also known as:** GHSA-342j-xgq4-rg29

## What is CVE-2026-8447?

CVE-2026-8447 is a medium-severity cross-site scripting vulnerability in Langflow Langflow, published on 4 Sep 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

IBM Langflow OSS 1.0.0 through 1.11.2 suffer from a stored cross-site scripting vulnerability in the Playground chat interface.

Weakness: CWE-79 (Improper Neutralization of Input During Web Page Generation)

## Which versions are affected by CVE-2026-8447?

It affects 1 product.


Products: Langflow Langflow.

## How do I fix CVE-2026-8447?

No fix has been published for CVE-2026-8447 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-8447 being exploited?

There is no known exploitation of CVE-2026-8447 in the wild and no public exploit code.

## Other vulnerabilities in Langflow Langflow

- [CVE-2026-9198](https://insights.sbomify.com/CVE-2026-9198/): IBM Langflow Code Injection (critical 9.8, exploited in the wild)
- [CVE-2026-0770](https://insights.sbomify.com/CVE-2026-0770/): Langflow Inclusion of Functionality from Untrusted Control Sphere (critical 9.8, exploited in the wild)
- [CVE-2025-3248](https://insights.sbomify.com/CVE-2025-3248/): Langflow Missing Authentication (critical 9.8, exploited in the wild)
- [CVE-2025-34291](https://insights.sbomify.com/CVE-2025-34291/): Langflow Origin Validation Error (critical 9.4, exploited in the wild)
- [CVE-2026-33017](https://insights.sbomify.com/CVE-2026-33017/): Langflow Code Injection (critical 9.3, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-8447 and fix it if it is affected.

What it is: CVE-2026-8447 is a medium-severity cross-site scripting vulnerability in Langflow Langflow, published on 4 Sep 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2026-8447 in the wild and no public exploit code.

Affected product: Langflow Langflow. 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-2026-8447/ (Markdown: https://insights.sbomify.com/CVE-2026-8447/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-8447
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-8447
- OSV: https://osv.dev/vulnerability/CVE-2026-8447

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-8447/
Summaries are generated and may contain mistakes; the official description above is the record.