Vulnerability in nltk (UBUNTU-CVE-2026-33230)
Summary
Vulnerability in nltk (UBUNTU-CVE-2026-33230). Risk of unauthorized operations or information disclosure. Exploitable via nltk.app.wordnet_app. Mitigation: upgrade to 2.0~b9-0ubuntu4.1~esm6 or later.
Original description
The description as published by the source.
NLTK (Natural Language Toolkit) is a suite of open source Python modules, data sets, and tutorials supporting research and development in Natural Language Processing. In versions 3.9.3 and prior, nltk.app.wordnet_app contains a reflected cross-site scripting issue in the lookup_... route. A crafted lookup_ URL can inject arbitrary HTML/JavaScript into the response page because attacker-controlled word data is reflected into HTML without escaping. This impacts users running the local WordNet Browser server and can lead to script execution in the browser origin of that application. Commit 1c3f799607eeb088cab2491dcf806ae83c29ad8f fixes the issue.
Source: OSV.dev (Open Source Vulnerabilities) OSV
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as UBUNTU-CVE-2026-33230 has been found in nltk.
Attackers can target a specific entry point like nltk.app.wordnet_app over the network to misuse the product.
Risk of unauthorized operations or information disclosure.
What to do: upgrade nltk to 2.0b9-0ubuntu4.1esm6 or later.
If unsure, ask your IT team or search "nltk UBUNTU-CVE-2026-33230" on the vendor's site.
UBUNTU-CVE-2026-33230 (nltk)
Attack vector: remote (network-reachable) / unauthenticated
Attack surface: nltk.app.wordnet_app / lookup_... / word
Patched: 2.0~b9-0ubuntu4.1~esm6 — apply immediately
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
A vulnerability (unclassified) exists in nltk. Attackers reach the vulnerable code path via nltk.app.wordnet_app without authentication.
Check the vendor advisory for the affected versions of nltk. Attack surface: nltk.app.wordnet_app / lookup_... / word.
Severity: ?. Risk of unauthorized operations or information disclosure.
Update to 2.0b9-0ubuntu4.1esm6.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'nltk' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
grep -r 'nltk' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
nltkを grep し、稼働しているサービス・バージョンを把握する。 -
2Apply patch patch
Upgrade nltk to 2.0~b9-0ubuntu4.1~esm6ステージング環境で 2.0
b9-0ubuntu4.1esm6 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。 -
3Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Affected packages
References
- advisory ubuntu.com
- report ubuntu.com
- report cve.org
- report github.com
- report github.com
- report github.com