{"id":"CVE-2026-118678","title":"n8n before 2.41.4 and 2.42.1 Prototype Pollution DoS via Workflow History Compaction","summary":"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 …","severity":"high","cvss":7.1,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:H","cvssSource":"cna","cwe":["CWE-1321"],"vendor":"n8n-io","product":"n8n","affected":["n8n < 2.41.4","n8n >= 2.42.0 < 2.42.1"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"partial","timestamp":"2026-10-29T15:28:50.969331Z"},"published":"2026-10-28","updated":"2026-10-29","sourceUpdated":"2026-10-29T20:54:29.021Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-118678","references":[{"url":"https://github.com/n8n-io/n8n/security/advisories/GHSA-fvv4-gmv9-xqf5","label":"GitHub Security Advisory (GHSA-fvv4-gmv9-xqf5)"},{"url":"https://www.vulncheck.com/advisories/n8n-before-2.41.4-and-2.42.1-prototype-pollution-dos-via-workflow-history-compaction","label":"VulnCheck Advisory: n8n before 2.41.4 and 2.42.1 Prototype Pollution DoS via Workflow History Compaction"}],"tags":["cve.org"],"epss":0.00293,"epssPercentile":0.2207,"ingestedAt":"2026-10-29T15:37:07.548Z","slug":"CVE-2026-118678","body":"## Overview\n\nn8n 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.\n\n## Affected\n\n- `n8n < 2.41.4`\n- `n8n >= 2.42.0 < 2.42.1`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":39,"depthScoreParts":{"impact":39.1,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}