# NLTK: Stable FrameNet and NKJP readers parse outside-root XML

Advisory record · `GHSA-568f-pv23-39p4`

- **Identifiers:** `GHSA-568f-pv23-39p4` · `CVE-2026-62385` · `PYSEC-2026-3728`
- **State:** Confirmed
- **Severity:** CVSS 8.2 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) · [CWE-706](https://cwe.mitre.org/data/definitions/706.html)
- **Tags:** [Path traversal](https://agentprime.io/advisories/tag/path-traversal.md) · [CWE-706](https://agentprime.io/advisories/tag/cwe-706.md)
- **Published:** 8 Sept 2026
- **Updated:** 8 Sept 2026
- **Reviewed by a person:** No

Published by the GitHub Advisory Database at 8 Sept 2026, 16:37 UTC. agentprime has not analysed this yet, so whether it affects any app is not known.

## Affected packages

- `nltk` (PyPI): affected `<3.10.0`; fixed in `3.10.0`

## Machine-written summary

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

> NLTK versions before 3.10.0 let the FrameNet and NKJP corpus readers parse XML files outside the corpus root. An application that passes attacker-influenced frame names, LU ids, NKJP file identifiers, or corpus index data to these readers can have outside-root XML content returned. Upgrade to NLTK 3.10.0.

Written 5 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

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

- **CISA KEV:** Not listed.
- **EPSS:** 0.0042, the 36th percentile, on 5 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

## Timeline

- 31 Oct 2026, 14:38 UTC: First seen by agentprime
- 31 Oct 2026, 14:38 UTC: [Confirmed by OSV](https://osv.dev/vulnerability/GHSA-568f-pv23-39p4)

## Sources

- [GitHub Advisory Database: GHSA-568f-pv23-39p4](https://github.com/advisories/GHSA-568f-pv23-39p4)
- [OSV: GHSA-568f-pv23-39p4](https://osv.dev/vulnerability/GHSA-568f-pv23-39p4)
- <https://github.com/nltk/nltk/security/advisories/GHSA-568f-pv23-39p4>
- <https://nvd.nist.gov/vuln/detail/CVE-2026-62385>
- <https://github.com/nltk/nltk/pull/3579>
- <https://github.com/nltk/nltk/pull/3581>
- <https://github.com/nltk/nltk/commit/7d1389d0789c1eca56bd0ed444089e0a3972e3ed>
- <https://github.com/nltk/nltk/commit/bf3bf32786791394a1008258b4917a7f2d4dbcda>
- <https://github.com/nltk/nltk>
- <https://github.com/nltk/nltk/releases/tag/v3.10.0>
- <https://github.com/pypa/advisory-database/tree/main/vulns/nltk/PYSEC-2026-3728.yaml>
- <https://www.vulncheck.com/advisories/nltk-path-traversal-via-framenet-and-nkjp-readers>

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-568f-pv23-39p4>, 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-568f-pv23-39p4/>. Everything for agents: <https://agentprime.io/llms.txt>.