# BlenderMCP path traversal in download_polyhaven_asset allows arbitrary file writes

Advisory record · `GHSA-4h8q-hh2j-755w`

- **Identifiers:** `GHSA-4h8q-hh2j-755w` · `CVE-2026-66004` · `PYSEC-2026-4203`
- **State:** Confirmed
- **Severity:** CVSS 6.0 Medium
- **Critical:** No
- **Weakness (CWE):** [CWE-22](https://cwe.mitre.org/data/definitions/22.html)
- **Tags:** [Path traversal](https://agentprime.io/advisories/tag/path-traversal.md)
- **Published:** 24 Jul 2026
- **Updated:** 15 Oct 2026
- **Reviewed by a person:** No

Published by the GitHub Advisory Database at 24 Jul 2026, 15:33 UTC. agentprime has not analysed this yet, so whether it affects any app is not known.

## Affected packages

- `blender-mcp` (PyPI): affected `<1.6.5`; fixed in `1.6.5`

## Machine-written summary

Summary written by Claude Haiku from the source advisory. Not reviewed by a person.

> BlenderMCP versions before 1.6.5 are vulnerable to path traversal in the download_polyhaven_asset method. An attacker who can perform a man-in-the-middle attack or inject prompts can supply traversal sequences in API response include keys, allowing arbitrary file writes that may lead to persistent code execution. Upgrade blender-mcp to version 1.6.5 or later.

Written 1 Nov 2026.

## 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

- 6.0 Medium, CVSS 4.0: `CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:P/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N`, from CNA (VulnCheck)

- **CISA KEV:** Not listed.
- **EPSS:** 0.0030, the 22nd percentile, on 14 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

## Timeline

- 31 Oct 2026, 14:08 UTC: First seen by agentprime
- 31 Oct 2026, 14:08 UTC: [Confirmed by OSV](https://osv.dev/vulnerability/GHSA-4h8q-hh2j-755w)

## Sources

- [GitHub Advisory Database: GHSA-4h8q-hh2j-755w](https://github.com/advisories/GHSA-4h8q-hh2j-755w)
- [OSV: GHSA-4h8q-hh2j-755w](https://osv.dev/vulnerability/GHSA-4h8q-hh2j-755w)
- <https://nvd.nist.gov/vuln/detail/CVE-2026-66004>
- <https://github.com/ahujasid/blender-mcp/issues/257>
- <https://github.com/ahujasid/blender-mcp/pull/258>
- <https://github.com/ahujasid/blender-mcp/commit/30a3308446cd8f81a9446e5a2ed657c0d8d86072>
- <https://github.com/ahujasid/mcp-for-blender>
- <https://www.vulncheck.com/advisories/blendermcp-path-traversal-via-download-polyhaven-asset-api>

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-4h8q-hh2j-755w>, 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-4h8q-hh2j-755w/>. Everything for agents: <https://agentprime.io/llms.txt>.