CVE-2026-110842

n8n before 2.41.4 and 2.42.x before 2.42.1 contains a prototype pollution vulnerability in the MCP workflow-validation tool, whose interpreter evaluates caller-supplied code in the main process, reads inherited properties, and permits assignment onto shared prototypes. An authenticated member holding only a workflow:read grant can replace a built-in method with one returning a truthy value so server-side permission checks accept unheld scopes, enabling takeover of owner accounts not protected by MFA.

CVSS 4.0

7.7CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

EPSS

0.3% chance of exploitation in the next 30 days; higher than 23% of CVEs (scores of 2026-10-25)

CWE

CWE-1321

Published

2026-10-14

Modified

2026-10-15

Record from

the NVD, synced 2026-10-19

References

• https://github.com/n8n-io/n8n/security/advisories/GHSA-5jr4-xmvf-frmj
• https://www.vulncheck.com/advisories/n8n-before-2.41.4-and-2.42.1-prototype-pollution-via-mcp-workflow-validation-interpreter

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