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CVE-2026-53957 high CVSS 7.7

SSRF (Server-Side Request Forgery) in @contentful/mcp-server (CVE-2026-53957)

Summary

SSRF in @contentful/mcp-server (CVE-2026-53957). Confidential information can be exposed externally. Exploitable via export_space. Mitigation: upgrade to 1.7.19 or later.

Original description

The description as published by the source.

Summary

export_space and import_space tools in @contentful/mcp-tools accept LLM-controlled host and proxy parameters that are spread directly into the options object passed to contentful-export / contentful-import. These libraries pass the merged options — including the attacker-controlled host — to the Contentful Management API (CMA) SDK, which builds baseURL from host and attaches the server's CMA Personal Access Token as Authorization: Bearer on every outgoing request. An attacker who can invoke MCP tools, or inject instructions into Contentful content the LLM reads, can redirect all CMA requests — and the PAT — to an attacker-controlled endpoint.

Details

Root cause — exportSpace.ts lines 126–141 (identical pattern in importSpace.ts lines 103–119):

// packages/mcp-tools/src/tools/jobs/space-to-space-migration/exportSpace.ts

const clientConfig    = createClientConfig(config);  // only extracts accessToken; discards config.host
const managementToken = clientConfig.accessToken;    // server's CMA PAT

const exportOptions = {
  ...args,          // ← LLM-controlled tool call args: args.host enters here, unfiltered
  managementToken,  // ← server PAT injected alongside attacker-controlled host
  environmentId: args.environmentId || 'master',
  exportDir:     args.exportDir     || process.cwd(),
  contentFile:   args.contentFile   || `contentful-export-${args.spaceId}.json`,
};

const contentfulExport = await import(…

Source: GitHub Security Advisories (Global) NVD GitHub Advisory

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 CVE-2026-53957 has been found in @contentful/mcp-server.
Attackers can target a specific entry point like export_space over the network to misuse the product.
Confidential information can be exposed externally. CVSS score: 7.7/10.
What to do: upgrade @contentful/mcp-server to 1.7.19 or later.
If unsure, ask your IT team or search "@contentful/mcp-server CVE-2026-53957" on the vendor's site.

CVE-2026-53957 (@contentful/mcp-server) — CWE-918 / CVSS v3 7.7
Attack vector: remote (network-reachable) / no user interaction
Attack surface: export_space / import_space / host / proxy
Patched: 1.7.19 — 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

SSRF (CWE-918) exists in @contentful/mcp-server. Attackers reach the vulnerable code path via export_space.

📍 Affected scope

Check the vendor advisory for the affected versions of @contentful/mcp-server. Attack surface: export_space / import_space / host / proxy.

🔥 Severity

Severity: High (CVSS 7.7/10). Confidential information can be exposed externally.

🔧 How to fix

Update to 1.7.19.

🛡️ 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 '@contentful/mcp-server' . 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

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

  2. 2
    Apply patch patch 
    Upgrade @contentful/mcp-server to 1.7.19

    ステージング環境で 1.7.19 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。

  3. 3
    Post-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

npm @contentful/mcp-server
[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"1.7.19"}]}]
npm @contentful/mcp-tools
[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"0.4.5"}]}]

References

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