n8n before 2.41.4 and 2.42.x before 2.42.1 contains a prototype pollution vulnerability in the MCP workflow-validation tool, whose interpreter evaluates caller-supplied code in the main process, reads inherited properties, and permits assignment onto shared prototypes. An authenticated member holding only a workflow:read grant can replace a built-in method with one returning a truthy value so server-side permission checks accept unheld scopes, enabling takeover of owner accounts not protected by MFA.
{
"cna_assigner": "VulnCheck",
"cwe_ids": [
"CWE-1321"
],
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/110xxx/CVE-2026-110842.json"
}{
"extracted_events": [
{
"introduced": "0"
},
{
"fixed": "2.41.4"
},
{
"introduced": "2.42.0"
},
{
"fixed": "2.42.1"
}
],
"source": "AFFECTED_FIELD"
}