CVE-2026-54052: n8n-MCP: Cross-tenant access to workflow version backups in multi-tenant HTTP deployments

Should you act?

Critical, preconditions apply

Severe if exploited, but exploitation needs conditions that may not apply to you. This signal is computed from CISA KEV, EPSS and CVSS data; it is not an editorial verdict.

• No confirmed exploitation. It is not in CISA’s KEV catalog and CISA’s SSVC assessment records no known exploitation. That can change quickly after a public write-up; re-check if you are affected.
• EPSS 0.4%, percentile 32: FIRST’s model estimates a 0.4% chance of exploitation activity in the next 30 days, higher than 32% of all scored CVEs (low). EPSS is a probability, not a verdict.
• Needs an account (low (any account)). Exposure depends on who can log in.
• Only applies if your dependency tree includes n8n-mcp (npm) <= 2.56.0, fixed in 2.56.1. Check your lockfile, including transitive dependencies.

What it is

n8n-MCP is an MCP server that provides AI assistants access to n8n node documentation, properties, and operations. Prior to 2.56.1, in HTTP mode with multi-tenancy enabled through ENABLEMULTITENANT=true, n8n-mcp's local workflow version history backups were not isolated per tenant, allowing an authenticated tenant to read workflow version snapshots belonging to other tenants and delete or destroy other tenants' stored backups, including full node definitions, credential references, and authorization headers. This issue is fixed in version 2.56.1.

From the GitHub advisory

Impact

In multi-tenant HTTP deployments — where a single n8n-mcp server serves several tenants — the locally stored workflow version history (the automatic backups taken before workflow updates) was not isolated per tenant. An authenticated tenant could read workflow version snapshots belonging to other tenants, and could delete or destroy other tenants' stored backups.

A stored snapshot includes full node definitions, so the exposed data can contain credential references and authorization headers configured on nodes. This is therefore a confidentiality issue in addition to an integrity/availability one.

Affected configurations

- HTTP mode with multi-tenancy enabled (ENABLEMULTITENANT=true), where multiple tenants are served by a single shared instance and database.

Weakness type: CWE-639, CWE-862.

Product: n8n-mcp (npm) · Assigned by: GitHub_M · Published: 2026-07-15

Affected and fixed versions

Severity scores

• Attack vector: network (remotely reachable)
• Attack complexity: low
• Privileges required: low (any account)
• User interaction: none
• Scope: changed (can affect other components)

CVSS measures how bad a flaw is if exploited, not how likely exploitation is. Read it next to the exploitation data below.

Exploitation and urgency

• CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
• CISA SSVC assessment: exploitation none, automatable no, technical impact total.
• FIRST EPSS (model of 2026-10-21): 0.39% probability of exploitation activity in the next 30 days; percentile 32.

Timeline

• 2026-07-14 — GitHub-reviewed advisory GHSA-j6r7-6fhx-77wx published (critical)
• 2026-07-15 — CVE record published by GitHub_M
• 2026-07-18 — CVE record last updated

Sources and references

Original sources first. Version and fix details should always be confirmed against the vendor or project advisory.

Vulnerability records

1. GitHub Advisory GHSA-j6r7-6fhx-77wx github.com
2. CVE.org record CVE-2026-54052 cve.org
3. NVD entry CVE-2026-54052 nvd.nist.gov

Other references from the CVE record and advisory

1. github.com github.com
2. github.com github.com

Critical npm advisories · Today’s Security Digest