CVE-2026-42236: n8n · Unthrottled Resource Allocation
Affects n8nSource CVE Database V5
Not known to be exploited · CVSS 8.7 High · fixed in 2.18.1 : patch n8n soon.
Data as of 31 Oct 2026, 20:20 UTC
- EPSS
- 0.4% chance of exploitation in 30 days – higher than 41% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 2.18.1, 2.17.4, 1.123.32
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 4 May 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 31 Oct 2026.
What to do
Upgrade n8n to 2.18.1, 2.17.4 or 1.123.32; n8n-io/n8n to 1.123.32.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| n8n-ion8n | Affected
| Fixed in
|
| n8n-ion8n | Affected
| Fixed in
|
| n8n-ion8n | Affected
| Fixed in
|
GitHubn8n-io/n8npkg:github/n8n-io/n8nOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
This vulnerability has been patched in n8n versions 1.123.32, 2.17.4, and 2.18.1. Users should upgrade to these or later versions to remediate the issue. No other mitigation or temporary workaround is indicated in the available data.
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.