CVE-2026-118678

high

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.

References

https://www.vulncheck.com/advisories/n8n-before-2.41.4-and-2.42.1-prototype-pollution-dos-via-workflow-history-compaction

https://github.com/n8n-io/n8n/security/advisories/GHSA-fvv4-gmv9-xqf5

https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-112384

Details

Source: Mitre, NVD

Published: 2026-10-28

Updated: 2026-10-29

Risk Information

CVSS v2

Base Score: 7.5

Vector: CVSS2#AV:N/AC:L/Au:S/C:N/I:P/A:C

Severity: High

CVSS v3

Base Score: 7.1

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

Severity: High

CVSS v4

Base Score: 7.1

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

Severity: High

EPSS

EPSS: 0.00293