CVE-2026-118678 n8n before 2.41.4 and 2.42.1 Prototype Pollution DoS via Workflow History Compaction
- Exploited in the wild
- Not known
- Fix
- None listed
What is CVE-2026-118678?
CVE-2026-118678 is a high-severity vulnerability in n8n-io n8n, published on 28 Oct 2026.
Official 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.
Weakness: CWE-1321
Which versions are affected by CVE-2026-118678?
How do I fix CVE-2026-118678?
No fix has been published for CVE-2026-118678 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-118678 being exploited?
There is no known exploitation of CVE-2026-118678 in the wild and no public exploit code.
Sources
Also known as GHSA-4v4v-jr32-r382, GHSA-fvv4-gmv9-xqf5.