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…
CVE-2026-118678
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.
Part of the AI stack
This affects n8n, in Agent frameworks.
Assessment
- CVSS
- 7.1 (v4.0)
- Severity
- High
- Known exploited
- Not listed in CISA KEV
- Exploit availability
- Nothing found in Exploit-DB, Metasploit, Nuclei or public PoC repositories
- Published
- 28 October 2026
- Last updated
- 29 October 2026
- Weakness
- CWE-1321
- Assigner
- disclosure@vulncheck.com
CVSS vectorCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
At the source
References
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