# NLTK: WekaClassifier passes an unvalidated caller-controlled model path to the weka JVM, bypassing nltk.pathsec containment

Advisory record · `GHSA-j456-xh4h-cpf2`

- **Identifiers:** `GHSA-j456-xh4h-cpf2` · `CVE-2026-109956`
- **State:** Confirmed
- **Severity:** CVSS 8.3 High
- **Critical:** No
- **Weakness (CWE):** [CWE-22](https://cwe.mitre.org/data/definitions/22.html) · [CWE-73](https://cwe.mitre.org/data/definitions/73.html)
- **Tags:** [Path traversal](https://agentprime.io/advisories/tag/path-traversal.md)
- **Published:** 27 Oct 2026
- **Updated:** 27 Oct 2026
- **Reviewed by a person:** No

Published by the GitHub Advisory Database at 27 Oct 2026, 14:50 UTC. agentprime has not analysed this yet, so whether it affects any app is not known.

## Affected packages

- `nltk` (PyPI): affected `<3.10.4`; fixed in `3.10.4`

## 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

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

- **CISA KEV:** Not listed.
- **EPSS:** 0.0032, the 24th percentile, on 5 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

## Timeline

- 31 Oct 2026, 14:07 UTC: First seen by agentprime
- 31 Oct 2026, 14:07 UTC: [Confirmed by OSV](https://osv.dev/vulnerability/GHSA-j456-xh4h-cpf2)

## Sources

- [GitHub Advisory Database: GHSA-j456-xh4h-cpf2](https://github.com/advisories/GHSA-j456-xh4h-cpf2)
- [OSV: GHSA-j456-xh4h-cpf2](https://osv.dev/vulnerability/GHSA-j456-xh4h-cpf2)
- <https://github.com/nltk/nltk/security/advisories/GHSA-j456-xh4h-cpf2>
- <https://github.com/nltk/nltk/pull/3863>
- <https://github.com/nltk/nltk/commit/6a17606293fe9d3ea1006f99dd3fed2e2b25d519>
- <https://github.com/nltk/nltk>
- <https://github.com/nltk/nltk/releases/tag/v3.10.4>

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-j456-xh4h-cpf2>, or `POST https://api.agentprime.io/v1/match` with your packages (<https://agentprime.io/api.md>)

---

The web page: <https://agentprime.io/advisories/GHSA-j456-xh4h-cpf2/>. Everything for agents: <https://agentprime.io/llms.txt>.