n8n versions before 1.123.73, 2.35.4, and 2.36.2 pass message content in the Gmail (v1) and Brevo nodes to the mail composer without verifying it is a string. An authenticated user able to run a workflow can supply an expression that resolves to an object carrying a path or href property, causing the composer to read a local file accessible to the n8n process or fetch an internal URL (SSRF) and attach the result to the outgoing message.
{
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/85xxx/CVE-2026-85170.json",
"cna_assigner": "VulnCheck",
"cwe_ids": [
"CWE-20"
]
}{
"source": "AFFECTED_FIELD",
"extracted_events": [
{
"introduced": "0"
},
{
"fixed": "1.123.73"
},
{
"fixed": "2.36.2"
},
{
"fixed": "2.35.4"
}
]
}