CVE-2026-77077
The runner's prototype-freezing routine covers globalThis functions but not internal module constructors such as EventEmitter, allowing an authenticated user with Code node access to exploit prototype pollution to execute arbitrary commands within the…
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.31%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
n8n versions before 1.123.69, 2.33.4, and 2.34.1 contain a JavaScript task runner VM sandbox escape. The runner's prototype-freezing routine covers globalThis functions but not internal module constructors such as EventEmitter, allowing an authenticated user with Code node access to exploit prototype pollution to execute arbitrary commands within the runner container. Because the polluted prototype is a process-wide object, the corruption persists across other tenants' Code node executions on the same shared runner. On v1.x instances without task runners enabled, Code node JavaScript runs directly in the main n8n process, where the impact could be higher.
- CVSS 4.0
- 7.2 HIGHCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:L/VA:L/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/M
- EPSS
- 0.31% probability · 24th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-94
- Affected
- n8n/n8n
- Source
- disclosure@vulncheck.com
References
- https://github.com/n8n-io/n8n/security/advisories/GHSA-m3hg-p5r9-fg9hMitigation, Vendor Advisory
- https://www.vulncheck.com/advisories/n8n-before-remote-code-execution-via-eventemitter-prototype-pollutionThird Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.