# Langflow has an Arbitrary File Write (RCE) via v2 API

Advisory record · `GHSA-g2j9-7rj2-gm6c`

- **Identifiers:** `GHSA-g2j9-7rj2-gm6c` · `CVE-2026-33309` · `PYSEC-2026-79`
- **State:** Confirmed
- **Severity:** CVSS 10.0 Critical
- **Critical:** Yes: CVSS 9+, CVSS 7+ and EPSS
- **Weakness (CWE):** [CWE-22](https://cwe.mitre.org/data/definitions/22.html) · [CWE-73](https://cwe.mitre.org/data/definitions/73.html) · [CWE-94](https://cwe.mitre.org/data/definitions/94.html) · [CWE-284](https://cwe.mitre.org/data/definitions/284.html)
- **Tags:** [Path traversal](https://agentprime.io/advisories/tag/path-traversal.md) · [Code injection](https://agentprime.io/advisories/tag/code-injection.md) · [Broken access control](https://agentprime.io/advisories/tag/access-control.md)
- **Published:** 19 Mar 2026
- **Updated:** 6 Jun 2026
- **Reviewed by a person:** No

Published by the GitHub Advisory Database at 19 Mar 2026, 17:46 UTC. agentprime has not analysed this yet, so whether it affects any app is not known.

## Critical

Critical, because:

- CVSS score 10.0: 9.0 or more.
- CVSS score 10.0 (7.0 or more) and EPSS 0.14 (0.1 or more): a high score and a real chance of exploitation in the next 30 days.

How we decide what’s critical: <https://agentprime.io/advisories/critical.md>

## Affected packages

- `langflow` (PyPI): affected `>=1.2.0, <1.9.0`; fixed in `1.9.0`

## Not analysed yet

We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.

## Severity and exploitation

- 10.0 Critical, CVSS 3.1: `CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H`, from CNA (GitHub_M)

- **CISA KEV:** Not listed.
- **EPSS:** 0.14, the 96th percentile, on 14 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

## Timeline

This record came from the full history of the GitHub Advisory Database, published 19 Mar 2026. New records show when each source confirmed them.

## Sources

- [GitHub Advisory Database: GHSA-g2j9-7rj2-gm6c](https://github.com/advisories/GHSA-g2j9-7rj2-gm6c)
- [OSV: GHSA-g2j9-7rj2-gm6c](https://osv.dev/vulnerability/GHSA-g2j9-7rj2-gm6c)
- <https://github.com/langflow-ai/langflow/security/advisories/GHSA-g2j9-7rj2-gm6c>
- <https://nvd.nist.gov/vuln/detail/CVE-2026-33309>
- <https://github.com/langflow-ai/langflow>
- <https://github.com/pypa/advisory-database/tree/main/vulns/langflow/PYSEC-2026-79.yaml>

Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code.

## Check whether this affects you

A Match means an installed version is in the affected range above. Most don’t affect the app; agentprime hasn’t analysed this one yet.

- With the agentprime MCP server (<https://api.agentprime.io/mcp>), ask your agent to check the project: `check_lockfile` sends a lockfile, `check_packages` a list of installed packages, and both return the Matches and the upgrades that clear them. `get_advisory` returns this record. Setup: <https://agentprime.io/mcp.md>
- In a browser: <https://agentprime.io/check/> reads your lockfile in the browser, never uploading it.
- Whether it touches your code, with file and line: the Claude Code plugin, <https://agentprime.io/plugin.md>
- As JSON: <https://api.agentprime.io/v1/advisories/GHSA-g2j9-7rj2-gm6c>, or `POST https://api.agentprime.io/v1/match` with your packages (<https://agentprime.io/api.md>)

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The web page: <https://agentprime.io/advisories/GHSA-g2j9-7rj2-gm6c/>. Everything for agents: <https://agentprime.io/llms.txt>.