HOMEVULNERABILITIESCVE-2026-42236
HIGH

CVE-2026-42236

CWE-770Published: May 4, 2026· Updated: May 6, 2026

7.5
CVSS v3.1
EPSS:0.14%probability of exploitation in 30 daysPercentile:33.7th

Official 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 Source

Technical Analysis

CVE-2026-42236 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

A successful exploit results in availability disruption (denial of service), with a CVSS base score of 7.5.

CVSS v3.1 Vector Breakdown

Exploitability
Attack VectorNetwork
Attack ComplexityLow
Privileges Req.None
User InteractionNone
ScopeUnchanged
Impact
ConfidentialityNone
IntegrityNone
AvailabilityHigh
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected Vendors & Products

n8n1 product
n8n
Source: NVD CPE · 2 total CPE entries

Exploit & PoC Resources

NO KNOWN EXPLOITNo public exploit confirmed at this time
Exploit-DB
Offensive Security exploit database
GitHub PoC Search
Community PoC repositories
Rapid7 / Metasploit
Metasploit module search
PacketStorm
Security advisories & exploits
NVD Detail
Official NIST entry
MITRE CVE
CVE Program entry
External links open in a new tab. Always verify in a controlled environment before use.

Official Patches & Advisories

ADVISORYhttps://github.com/n8n-io/n8n/security/advisories/GHSA-49m9-pgww-9vq6

All References (1)

→
https://github.com/n8n-io/n8n/security/advisories/GHSA-49m9-pgww-9vq6Vendor Advisory

Quick Facts

CVE IDCVE-2026-42236
CVSS Score7.5 / 10
SeverityHIGH
WeaknessCWE-770
CISA KEVNo
EPSS (30d)0.14%
Affected1 vendor
PublishedMay 4, 2026

Related CVEs (CWE-770)

CVE-2026-42786
8.7
CVE-2026-32689
8.7
CVE-2026-48854
8.7
CVE-2026-44499
8.7
CVE-2026-39803
8.7
CVE-2026-39313
8.7

Recommended Actions

  • →Apply vendor patches immediately
  • →Monitor CVE-2026-42236 in threat intel feeds
  • →Review IDS/IPS signatures for exploitation attempts
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWATCH.COM. CVE data is provided under the NVD usage policy.
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