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CVE-2026-0846
high
CVSS 7.5
Vulnerability in nltk (CVE-2026-0846)
Summary
vulnerability in nltk (CVE-2026-0846). Confidential information can be exposed externally. Exploitable via ``nltk.util``. Mitigation: upgrade to `3.9.3` or later.
AI summary snake-internal / snake-material-v2
A vulnerability tracked as **CVE-2026-0846** has been found in nltk.
Attackers can target a specific entry point like ``nltk.util`` over the network to misuse the product.
Confidential information can be exposed externally. CVSS score: 7.5/10.
What to do: upgrade nltk to **3.9.3** or later.
If unsure, ask your IT team or search "nltk CVE-2026-0846" on the vendor's site.
CVE-2026-0846 (nltk) — CWE-36 / CVSS v3 7.5
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Attack surface: `nltk.util`
Patched: `3.9.3` — 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.
❓ What is the problem
**A vulnerability** (CWE-36) exists in nltk. Attackers reach the vulnerable code path via ``nltk.util`` without authentication.
📍 Affected scope
nltk — . Attack surface: `nltk.util`.
🔥 Severity
Severity: High (CVSS 7.5/10). Confidential information can be exposed externally
🔧 How to fix
Update to **3.9.3**.
🛡️ Workaround
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
🔍 Detection
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 (7 steps)
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。
-
6Apply patch patch
Upgrade nltk to 3.9.3ステージング環境で 3.9.3 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と、Step 3 で見つけた異常検知の続報チェックを含めること。
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7Post-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 Step 3 と同じログクエリでアラート再発が無いか継続監視。
Affected packages
PyPI
nltk
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"last_affected":"3.9.2"}]}]
pip
nltk
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.9.3"}]}]
References
- advisory https://nvd.nist.gov/vuln/detail/CVE-2026-0846
- advisory https://github.com/advisories/GHSA-h8wq-7xc4-p3qx
- exploit 134c704f-9b21-4f2e-91b3-4a467353bcc0
- package https://github.com/nltk/nltk
- web https://github.com/nltk/nltk/pull/3485
- web https://github.com/nltk/nltk/commit/b2e1164bf89277f79b65406c829b99fb20ca1974
- web https://github.com/pypa/advisory-database/tree/main/vulns/nltk/PYSEC-2026-97.yaml
- web 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- web 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- web 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- web 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- web 0b0ca135-0b70-47e7-9f44-1890c2a1c46c