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CVE-2026-42271 CISA KEV high CVSS 8.8

[KEV] Command Injection in Berriai litellm (CVE-2026-42271)

Summary

command injection in Berriai litellm (CVE-2026-42271). Successful exploitation can lead to full system takeover. Exploitable via `POST /mcp-rest/test/connection`. Listed in CISA KEV — actively exploited. Mitigation: upgrade to `1.83.7` or later.

AI summary snake-internal / snake-material-v2

A vulnerability tracked as **CVE-2026-42271** has been found in Berriai litellm. Attackers can target a specific entry point like `POST /mcp-rest/test/connection` over the network to misuse the product. Successful exploitation can lead to full system takeover. CVSS score: 8.8/10. Note: CISA has officially confirmed this is **actively exploited in the wild**. Treat it with elevated urgency. What to do: upgrade Berriai litellm to **1.83.7** or later. If unsure, ask your IT team or search "Berriai litellm CVE-2026-42271" on the vendor's site.
CVE-2026-42271 (Berriai litellm) — CWE-77 / CVSS v3 8.8 Attack vector: remote (network-reachable) / no user interaction Attack surface: POST /mcp-rest/test/connection / POST /mcp-rest/test/tools/list / `command` / `args` Patched: `1.83.7` — apply immediately Listed in CISA KEV — actively exploited, treat as top priority. Workaround: If upgrading is not immediately possible, developers should block `POST /mcp-rest/test/connection` and `POST /mcp-rest/test/tools/list` at their reverse proxy or API gateway. 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-77) exists in Berriai litellm. Attackers reach the vulnerable code path via `POST /mcp-rest/test/connection` without authentication.
📍 Affected scope
Berriai litellm — . Attack surface: POST /mcp-rest/test/connection / POST /mcp-rest/test/tools/list / `command` / `args`.
🔥 Severity
Severity: High (CVSS 8.8/10). Successful exploitation can lead to full system takeover **Listed in CISA KEV** — actively exploited in the wild, treat as top priority.
🔧 How to fix
Update to **1.83.7**.
🛡️ Workaround
Workaround: If upgrading is not immediately possible, developers should block `POST /mcp-rest/test/connection` and `POST /mcp-rest/test/tools/list` at their reverse proxy or API gateway.
🔍 Detection
Search webserver/proxy logs for unusual `POST /mcp-rest/test/connection` requests with malformed payloads or SQL meta-characters. Run `grep -r 'litellm' .` 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

  1. 1
    Identify exposure identify
    grep -r 'litellm' . | 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 `litellm` を grep し、稼働しているサービス・バージョンを把握する。

  2. 3
    Hunt for indicators of compromise detect
    grep 'POST /mcp-rest/test/connection' /var/log/nginx/access.log | grep -E '(unusual_payload|sqli_pattern)'

    アクセスログで `POST /mcp-rest/test/connection` への異常なリクエスト (不正な認証ヘッダ・SQLメタ文字)を過去 30〜90日分捜索。WAF/SIEM があれば該当パスのアラート発火履歴を確認。

  3. 4
    Consider incident declaration escalate
    Notify SOC / on-call

    CISA KEV登録済 = 実環境で悪用が観測されている。Step 3 で兆候があればインシデント対応宣言、無くてもパッチ適用までWAF強化を最優先で。

  4. 5
    Apply temporary workaround mitigate
    If upgrading is not immediately possible, developers should block `POST /mcp-rest/test/connection` and `POST /mcp-rest/test/tools/list` at their reverse proxy or API gateway.

    パッチが適用されるまでの応急処置として、If upgrading is not immediately possible, developers should block `POST /mcp-rest/test/connection` and `POST /mcp-rest/test/tools/list` at their reverse proxy or API gateway. を実施。回避策の副作用 (機能低下) を確認した上で。

  5. 6
    Apply patch patch
    Upgrade litellm to 1.83.7

    ステージング環境で 1.83.7 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。

  6. 7
    Post-deployment verification verify
    Replay attack against POST /mcp-rest/test/connection on staging to confirm patch closes the vector

    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

pip litellm
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.83.7"}]}]
PyPI litellm
[{"type":"ECOSYSTEM","events":[{"introduced":"1.74.2"},{"fixed":"1.83.7"}]}]

References

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