n8n: Send Email Node Arbitrary File Read and SSRF via Nodemailer Content-Object Type Confusion
n8n
- Severity
- High, CVSS 8.2
- CVSS vector
- CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:L/SI:N/SA:N
- Record
- GHSA-2x35-3fw4-9jr4
- Affects
- n8n
- Known exploited
- Not listed in the CISA Known Exploited Vulnerabilities catalog
- Published
- Record first published by the source
- July 22, 2026
- Source last modified
- July 22, 2026
Description
Impact
The n8n Send Email node did not enforce that its message fields were strings, so a crafted untrusted non-string value from a workflow expression could be treated by the underlying mail library as a file path or URL. This could allow disclosure of local files on the n8n host.
Exploitation requires a pre-existing active workflow with an unauthenticated webhook, valid SMTP credentials configured on the Send Email node, and untrusted input mapped directly into the text or HTML body field. This is not a default n8n configuration.
Patches
The issue has been fixed in n8n versions 1.123.67, 2.31.5, and 2.32.1. Users should upgrade to one of these versions or later to remediate the vulnerability.
Workarounds
If upgrading is not immediately possible, administrators should consider the following temporary mitigations: - Audit active workflows for Send Email nodes that map untrusted webhook or external data directly into the text or HTML body fields, and remove or restrict those workflows. - Restrict public webhook access at the network or reverse-proxy level to prevent unauthenticated callers from reaching sensitive workflows. - Restrict workflow creation and editing permissions to fully trusted users only.
These workarounds do not fully remediate the risk and should only be used as short-term mitigation measures.
Description quoted from the GitHub Advisory Database.
Who is affected
n8n is a tool for automating tasks by connecting different apps and online services into step-by-step workflows. This flaw is in the Send Email step, which sends emails from a workflow. An attacker could use it to read files stored on the computer or server running n8n. It only works when all of these are true: an active workflow can be started by anyone without logging in, the Send Email step has working email account details set up, and outside input goes straight into the email's text or HTML body. This is not how n8n is set up by default. This flaw is rated High.
What to do
- The person who installed or runs n8n for your organization should update it to version
1.123.67,2.31.5or2.32.1, or a later version. - If an IT provider or vendor runs n8n for you, send them this advisory and ask when the update will be done.
- Until you can update, check active workflows for Send Email steps that put outside webhook or external data directly into the text or HTML body fields, and remove or restrict those workflows.
- Also until then, limit public webhook access (the links that let outside callers start a workflow) at the network or reverse-proxy level so callers who are not logged in cannot reach sensitive workflows. Allow only fully trusted users to create or edit workflows. These steps lower the risk but do not remove it.
Analysis written from the source record as of July 22, 2026 and reviewed before publishing.