# Duplicate Advisory: nltk: SSRF Fail-Open in validate_network_url() via DNS Resolution Failure

Advisory record · `GHSA-qg9p-xrhj-435m` · Withdrawn

- **Identifiers:** `GHSA-qg9p-xrhj-435m`
- **State:** Withdrawn
- **Severity:** CVSS 5.3 Medium
- **Critical:** No
- **Weakness (CWE):** [CWE-918](https://cwe.mitre.org/data/definitions/918.html)
- **Tags:** [Server-side request forgery (SSRF)](https://agentprime.io/advisories/tag/ssrf.md)
- **Published:** 22 Aug 2026
- **Updated:** 2 Sept 2026
- **Reviewed by a person:** No

**Withdrawn.** The GitHub Advisory Database withdrew this advisory on 2 Sept 2026. The record stays here, marked withdrawn.

Published by the GitHub Advisory Database at 22 Aug 2026, 15:31 UTC. agentprime has not analysed this yet, so whether it affects any app is not known.

## Affected packages

- `nltk` (PyPI): affected `<=3.9.4`; no fixed version yet

## 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

- 5.3 Medium, CVSS 3.1: `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N`, from GitHub Advisory Database

- **CISA KEV:** Not listed.
- **EPSS:** No score.

## 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-qg9p-xrhj-435m)

## Sources

- [GitHub Advisory Database: GHSA-qg9p-xrhj-435m](https://github.com/advisories/GHSA-qg9p-xrhj-435m)
- [OSV: GHSA-qg9p-xrhj-435m](https://osv.dev/vulnerability/GHSA-qg9p-xrhj-435m)
- <https://github.com/nltk/nltk/security/advisories/GHSA-3gqm-fcw5-w839>
- <https://nvd.nist.gov/vuln/detail/CVE-2026-63311>
- <https://www.vulncheck.com/advisories/nltk-before-ssrf-via-dns-resolution-failure>

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-qg9p-xrhj-435m>, 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-qg9p-xrhj-435m/>. Everything for agents: <https://agentprime.io/llms.txt>.