Read the docs
TI-2026-82167 Aliases CVE-2026-118678GHSA-4v4v-jr32-r382

Prototype pollution in n8n workflow history compaction causes denial of service

Priority LOW 31CWE-1321Published · Updated

Key facts

Attack vector
Network
Privileges required
Low
User interaction
None
Attack complexity
Low
Attack requirements
None
Impact type
—
Confidentiality · integrity · availability
None · Low · High
Fix status
Fixed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA.

Summary

n8n before 2.41.4 and 2.42.x before 2.42.1 contains a prototype pollution flaw (CWE-1321) that lets low-privileged users alter built-in object behaviour by saving workflows with specially named connection keys such as __proto__. The periodic workflow history compaction task processes these keys, causing logins and writes to fail with server errors. An attacker with low privileges can exploit this over the network without user interaction.

Written with Claude Haiku 5.5 from the sources below · 2026-10-29

Description from the CNA

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00293 22nd percentileScored 2026-11-07
Fix Fixed n8n (n8n-io): 2.41.4, 2.42.1

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
n8nn8nbefore 2.41.42.41.4Patch availableCNA
n8nn8n2.42.0 to before 2.42.12.42.1Patch availableCNA
  • n8n Vendorn8n Affected before 2.41.4 Fixed in 2.41.4 Patch available CNA
  • n8n Vendorn8n Affected 2.42.0 to before 2.42.1 Fixed in 2.42.1 Patch available CNA

CPE names Threatist (inferred) · 1

Inferred from how NVD named this product before; not given by a source.

CPEVersionsRoleVendor
cpe:2.3:a:n8n:n8n:*:*:*:*:*:*:*:*——n8n
  • cpe:2.3:a:n8n:n8n:*:*:*:*:*:*:*:* Versions — — ·n8n

Remediation

Upgrade n8n to version 2.41.4 or 2.42.1, whichever fixes the installed release.

Written with Claude Haiku 5.5 from the sources below · 2026-10-29

  • Fix · CNA n8n (n8n-io) Fixed in 2.41.4
  • Fix · CNA n8n (n8n-io) Fixed in 2.42.1

Fixed in the same release

Records fixed by the same vendor advisory or release, as the CNA lists them.

  • Release ·

    n8n-io n8n 2.41.4, 2.42.1

    3 records Highest priority Priority LOW 3 LOW

    Other records, highest priority first

    • TI-2026-82168 Server-side request forgery in n8n Slack Trigger leaks Slack tokensPriority LOW 30
    • TI-2026-82166 n8n Local Gateway deep link silently re-pairs to attacker instancePriority LOW 26
    Show all 3 records →

Timeline

  1. 2026-10-28 Threatist record created from CVE-2026-118678
  2. 2026-10-28 Alias added: GHSA-4v4v-jr32-r382
  3. 2026-10-29 CISA SSVC decision points changed
  4. 2026-10-29 Priority changed: MEDIUM → LOW

References

Advisory 1

  • TI-2025-42131 n8n Vulnerable to Remote Code Execution via Expression Injection KEVCVSS 3.1CRITICAL 10.0
  • TI-2026-17560 n8n Vulnerable to Unauthenticated File Access via Improper Webhook Request Handling CVSS 3.1CRITICAL 10.0
  • TI-2026-01167 Authenticated users can bypass the Expression sandbox mechanism to achieve full remote… CVSS 3.1CRITICAL 9.9
  • TI-2026-00644 Sandbox escape in n8n Python task runner allows for arbitrary code execution on the underlying host. CVSS 3.1CRITICAL 9.9
  • TI-2026-82991 Code execution in n8n via deprecated Function nodes CVSS 4.0HIGH 8.7
  • TI-2025-35293 An arbitrary file upload vulnerability in the Chat Trigger component of N8N v1.95.3… CVSS 3.1HIGH 8.8
See all 233 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences