CVE-2026-118678 — HIGH (7.1)

Vulnerability Description

n8n before 2.41.4 and 2.42.x before 2.42.1 contains a prototype pollution vulnerability that allows low-privileged users to alter built-in object behaviour by saving workflows with specially named connection keys. Attackers can add keys such as __proto__ to workflow connections, which the periodic history compaction task processes, causing logins and writes to fail with server errors.

CVSS Score

7.1

HIGH

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:H

Attack Vector

NETWORK

Attack Complexity

LOW

Privileges Required

LOW

User Interaction

NONE

Scope

UNCHANGED

Confidentiality

NONE

Integrity

LOW

Availability

HIGH

Related Weaknesses (CWE)

CWE-1321

References

FAQ

What is CVE-2026-118678?

CVE-2026-118678 is a vulnerability with a CVSS score of 7.1 (HIGH). n8n before 2.41.4 and 2.42.x before 2.42.1 contains a prototype pollution vulnerability that allows low-privileged users to alter built-in object behaviour by saving workflows with specially named con...

How severe is CVE-2026-118678?

CVE-2026-118678 has been rated HIGH with a CVSS base score of 7.1/10. Review the CVSS metrics above for detailed severity breakdown.

Is there a patch for CVE-2026-118678?

Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.