n8n before 1.123.83, 2.41.4, and 2.42.1 Prototype Pollution via AI Workflow Builder Connection Merge

CISA KEV is observed exploitation evidence. FIRST EPSS is a dated prediction of exploitation in the next 30 days. Missing scores are unknown. This collector requests predictions only for explicit CVE aliases in the public NuGet archive; Microsoft release views retain their existing prediction scope.

No collected risk observation for these identifiers. This does not establish absence of exploitation or a zero probability.

n8n before 1.123.83, 2.x before 2.41.4, and 2.42.x before 2.42.1 contains a prototype pollution vulnerability in the AI workflow builder, which merges workflow connections using node names as object members without checking for reserved keys. Authenticated users can create nodes named __proto__ through the API and invoke the connect-nodes operation to pollute the global object prototype, disrupting the instance until restart.

Source published

14 Oct 2026 22:52:23 UTC

Source modified

16 Oct 2026 17:14:56 UTC

Observed here

23 Oct 2026 15:48:27 UTC

Source terms

CVE Program Terms of Use

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CVSS 4.0 · 6.0 CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N