n8n: Merge Node SQL Mode Prototype Pollution
n8n
- Severity
- High, CVSS 7.7
- CVSS vector
- CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N
- Record
- CVE-2026-54311
- Affects
- n8n
- Known exploited
- Not listed in the CISA Known Exploited Vulnerabilities catalog
- Published
- Record first published by the source
- June 23, 2026
- Source last modified
- October 26, 2026
Description
n8n is an open source workflow automation platform. Prior to 2.25.7 and 2.26.2, an authenticated user with permission to create or modify workflows could pollute the sandbox used by the Merge node's SQL Query mode. Because the sandbox context was cached and reused across all workflow executions on the instance, prototype mutations introduced by one user's workflow persist into subsequent Merge SQL executions belonging to other users or projects. This allowed a low-privileged attacker to intercept workflow data processed by other users on the same instance. This issue only affects multi-user n8n instances where more than one user has permission to create and execute workflows containing the Merge node in SQL Query mode. This vulnerability is fixed in 2.25.7 and 2.26.2.
Description quoted from the NVD record.
Who is affected
n8n is a tool for automating tasks by linking apps and services into step-by-step workflows. This flaw affects versions before 2.25.7 and 2.26.2. It applies only to n8n setups shared by several users, where more than one person can create and run workflows that use the Merge step in its SQL Query mode. A signed-in user who is allowed to create or change workflows could tamper with that feature and intercept workflow data that other users or projects process on the same setup. This flaw is rated High.
What to do
- The person who installed or runs n8n for your organization should check which version is in use and whether more than one person can create and run workflows on it.
- If it is older than the fixed releases, update n8n to version
2.25.7or2.26.2, which fix this flaw. - If an IT provider or vendor runs n8n for your organization, send them this advisory and ask when the update will be done.
- If only one person can create and run workflows on your n8n setup, this flaw does not apply, but plan the update anyway.
Analysis written from the source record as of October 26, 2026 and reviewed before publishing.