Security readout for executives and security teams
Plain-English summary
CVE-2026-45707 lets an authenticated tenant of a shared n8n-MCP HTTP service accidentally or deliberately run n8n management actions against the operator’s own n8n instance when tenant headers are missing or incomplete. It affects multi-tenant HTTP deployments before 2.51.2, not single-tenant deployments.
Executive priority
Treat this as urgent for any organization offering n8n-mcp as a shared tenant service. The main business risk is cross-tenant access to the operator’s automation platform using privileged configured credentials.
Technical view
In n8n-mcp before 2.51.2, ENABLE_MULTI_TENANT=true HTTP transport selected tenant targets from x-n8n-url and x-n8n-key headers. Missing or partial headers silently fell back to process-level N8N_API_URL and N8N_API_KEY, causing authenticated tenant requests to use operator credentials. CVSS is 8.1 high, CWE-284.
Likely exposure
Exposure is limited to shared HTTP-mode n8n-mcp services running versions before 2.51.2 with ENABLE_MULTI_TENANT=true. Deployments with ENABLE_MULTI_TENANT unset or false are stated as not affected.
Exploitation context
The provided sources do not show known active exploitation, and KEV is false. Exploitation requires authenticated MCP tenant access, but no user interaction and low complexity are indicated by the CVSS vector.
Researcher notes
The key condition is fallback behavior when x-n8n-url or x-n8n-key is absent or incomplete. Focus validation on configuration, transport mode, version, request logs, and whether operator-level N8N_API_URL/N8N_API_KEY were reachable through tenant traffic.
Mitigation direction
- Upgrade n8n-mcp to version 2.51.2 or later.
- Inventory shared HTTP-mode deployments with ENABLE_MULTI_TENANT=true.
- Avoid shared multi-tenant HTTP operation until upgraded if exposure cannot be controlled.
- Review vendor advisory and release notes for deployment-specific guidance.
- Investigate suspicious tenant activity before reusing operator n8n API credentials.
Validation and detection
- Check deployed n8n-mcp versions and flag anything below 2.51.2.
- Confirm whether ENABLE_MULTI_TENANT=true is set in runtime configuration.
- Identify whether the service is exposed as shared HTTP transport for multiple tenants.
- Review logs for authenticated requests missing one or both tenant headers.
- Check for management actions landing on the operator n8n instance unexpectedly.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
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ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-284: Authorization and privilege behavior lookup
Authorization weaknesses can support privilege escalation and valid-account review, depending on exploit path. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2026-45707 mapping review
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Open ATT&CK lookup- Severity
- High
- CVSS
- 8.1 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
CNA and ADP enrichment extracted from CVE v5
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SSVC decision data
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N2.85.2GitHub_MVulnerability scoring details
Base CVSS 3.1 score
8.1HighVector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- CVE publishedCVE Program
The CVE record was published.
- CVE updatedCVE Program
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ADP provider summaries
Source materials
- CVE List V5 sourceCVE List V5
- https://github.com/czlonkowski/n8n-mcp/security/advisories/GHSA-jxx9-px88-pj69CVE reference, GitHub_M · x_refsource_CONFIRM
- https://github.com/czlonkowski/n8n-mcp/commit/853015d0897be7cf2d9d4726de195c938e4395abCVE reference, GitHub_M · x_refsource_MISC
- https://github.com/czlonkowski/n8n-mcp/releases/tag/v2.51.2CVE reference, GitHub_M · x_refsource_MISC
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Improper Access Control
Improper Access Control represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.