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.
CVE-2026-77077
HIGHPre-NVD 7.27.2
EchelonGraph scoreLOW confidence
This high-severity CVE scores 7.2 under the CNA's CVSS (NVD's own analysis pending). EPSS exploit-prediction score not yet available (the EPSS model rescores nightly; freshly-published CVEs typically appear within 48 hours). GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).
Triggered by: NVD CVSS baseline
Sources: cna:vulncheck
7.2EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
- High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: —CVSS: 7.2Exploit: None knownExposed: 0
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 7.2
- EG Score
- 7.2(low)
- EG Risk
- 37(Track)EG Risk 37/100SSVC: Track
EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).
How it’s computedSeverity72% × 45%Exploitation0% × 40%Automatability30% × 15%Action: Routine — remediate on your standard cadence. - EPSS PROB
- —
- EPSS %ILE
- —
- KEV
- Not listed
Published
August 20, 2026
Last Modified
August 20, 2026
Advisory Details (2)
Auto-updated Aug 20, 2026Patch available. Sources: github.
generic
n8n before 1.123.69 Remote Code Execution via EventEmitter Prototype Pollution | Advisories | VulnCheck
https://www.vulncheck.com/advisories/n8n-before-remote-code-execution-via-eventemitter-prototype-pollutiongithub Patch Available
JavaScript Task Runner VM Sandbox Escape via EventEmitter Prototype Pollution Leads to Remote Code Execution · Advisory · n8n-io/n8n · GitHub
https://github.com/n8n-io/n8n/security/advisories/GHSA-m3hg-p5r9-fg9hWeakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 2× in last 7d / 2× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
- 2026-08-20 11:37 UTCEG score recompute
- 2026-08-20 11:36 UTCMITRE cvelistV5first tracked
Frequently asked(4)
What is CVE-2026-77077?
CVE-2026-77077 is a high vulnerability published on August 20, 2026. 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…
When was CVE-2026-77077 disclosed?
CVE-2026-77077 was first published in the National Vulnerability Database on August 20, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
What is the CVSS score of CVE-2026-77077?
CVE-2026-77077 has a CVSS v4.0 base score of 7.2 (CNA self-assessment; NVD's own analysis pending). The EG score is currently aggregating — additional source signals are being incorporated as they become available..
How do I remediate CVE-2026-77077?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-77077, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.
Dependency Blast Radius
Explore the affected products and dependency analysis for CVE-2026-77077
Is Your Infrastructure Affected by CVE-2026-77077?
EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.