CVE-2026-42236
Essential information
- Published
- 04/05/2026 19:16
- Modified
- 04/05/2026 19:16
- Author
- —
- Creator
- —
- CVSS
- 8.7 HIGH (v3) 8.7 HIGH (v4.0)
- CISA KEV
- No
- CWE
- —
- CVSS vector
-
—
—
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CVSS metrics
- Access vector
- —
- Access complexity
- —
- Authentication
- —
- Confidentiality impact
- —
- Integrity impact
- —
- Availability impact
- —
- Exploitability
- —
- Remediation level
- —
- Report confidence
- —
- Temporal score
- —
- Attack vector
- —
- Attack complexity
- —
- Privileges required
- —
- User interaction
- —
- Scope
- —
- Confidentiality impact
- —
- Integrity impact
- —
- Availability impact
- —
- Exploit code maturity
- —
- Remediation level
- —
- Report confidence
- —
- Temporal score
- —
- Attack vector
- NETWORK
- Attack complexity
- LOW
- Attack requirements
- NONE
- Privileges required
- NONE
- User interaction
- NONE
- Confidentiality (V)
- NONE
- Confidentiality (S)
- NONE
- Integrity (V)
- NONE
- Integrity (S)
- NONE
- Availability (V)
- HIGH
- Availability (S)
- NONE
- Exploit maturity
- NOT_DEFINED
Description
n8n is an open source workflow automation platform. Prior to versions 1.123.32, 2.17.4, and 2.18.1, the MCP OAuth client registration endpoint accepted unauthenticated requests and stored client data without adequate resource controls. An unauthenticated remote attacker could exhaust server memory resources by sending large registration payloads, rendering the n8n instance unavailable. The MCP enable/disable toggle gates MCP access but did not restrict client registrations, meaning the endpoint is reachable regardless of whether MCP access is enabled on the instance. This issue has been patched in versions 1.123.32, 2.17.4, and 2.18.1.
NVD status
- Status
- Received — CVE has been recently published to the CVE List and has been received by the NVD.
- Source
- [email protected]
- NVD
- View on NVD
Affected products (CPE)
| Product | CPE |
|---|---|
| n8n / n8n | cpe:2.3:a:n8n:n8n:<1.123.32:*:*:*:*:*:*:* |
| n8n / n8n | cpe:2.3:a:n8n:n8n:<2.17.4:*:*:*:*:*:*:* |
| n8n / n8n | cpe:2.3:a:n8n:n8n:<2.18.1:*:*:*:*:*:*:* |