{"data":{"id":"679a4d83-12c4-4b26-b4ee-b692b8565fe6","title":"GHSA-679f-58pq-4v2c: n8n: Prototype Pollution via Workflow Structure Summary Can Lead to Denial of Service","summary":"The Instance AI workflow summary in n8n built its result using get-or-create-then-nested-write logic keyed by node names and connection keys from stored workflows. Because the editor's restricted-name guard is client-side, an attacker can post a workflow with a reserved key such as `__proto__` directly to the REST API, so the write lands on `Object.prototype` in the main n8n process and affects every later request. The advisory covers this prototype pollution flaw, which can lead to denial of service.","solution":"Fixed in n8n versions 2.37.7 and 2.38.2; upgrade to one of these or later. If upgrading is not immediately possible, restrict instance access to fully trusted users, remove or leave unconfigured the `N8N_INSTANCE_AI_MODEL*` environment variables, and restart the n8n process to clear in-memory pollution if an attack is suspected. These workarounds do not fully remediate the risk and are short-term measures only.","labels":["security"],"sourceUrl":"https://github.com/advisories/GHSA-679f-58pq-4v2c","publishedAt":"2026-09-10T21:05:24.000Z","cveId":"CVE-2026-86078","cweIds":null,"cvssScore":null,"cvssSeverity":"medium","severity":"medium","attackType":["other"],"issueType":"vulnerability","affectedPackages":["n8n@< 2.37.7 (fixed: 2.37.7)","n8n@>= 2.38.0, < 2.38.2 (fixed: 2.38.2)"],"affectedPackageNames":["n8n"],"affectedPackageRefs":["npm:n8n"],"affectedVendors":[],"affectedVendorsRaw":["n8n","Instance AI"],"classifierModel":"claude-haiku-5-5","classifierPromptVersion":"v4","summaryPromptVersion":"v2","headline":null,"headlinePromptVersion":null,"cvssVector":null,"attackVector":null,"attackComplexity":null,"privilegesRequired":null,"userInteraction":null,"exploitMaturity":"unknown","epssScore":0.00586,"epssCheckedAt":"2026-11-05T06:10:14.448Z","kevDateAdded":null,"advisoryAliases":["GHSA-679f-58pq-4v2c"],"affectedPackagesSource":null,"affectedPackagesCheckedAt":null,"patchAvailable":true,"disclosureDate":"2026-09-10T21:05:24.000Z","fixReleasedAt":"2026-09-02T07:38:30.231Z","daysToFix":-8,"fixCheckedAt":"2026-10-29T21:30:47.016Z","capecIds":null,"crossRefCount":0,"attackSophistication":"moderate","impactType":["availability","integrity"],"aiComponentTargeted":"plugin","llmSpecific":false,"classifierConfidence":0.7,"researchCategory":null,"atlasIds":null,"fixes":[{"ecosystem":"npm","name":"n8n","fixedVersion":"2.38.2","matchedVersion":"2.38.2","fixReleasedAt":"2026-09-02T07:38:30.231Z","daysToFix":-8,"match":"ecosystem","source":"tracked","status":"found","checkedAt":"2026-10-29T21:30:46.870Z"},{"ecosystem":"npm","name":"n8n","fixedVersion":"2.37.7","matchedVersion":"2.37.7","fixReleasedAt":"2026-09-02T08:04:03.094Z","daysToFix":-8,"match":"ecosystem","source":"tracked","status":"found","checkedAt":"2026-10-29T21:30:46.870Z"}]}}