CVE-2026-72769 — n8n before 1.123.67 Prototype Pollution via VM Expression Engine
n8n before 1.123.67, 2.31.5, and 2.32.1 contains a prototype pollution vulnerability in the VM expression engine. An authenticated user able to create or edit a workflow expression can abuse the engine's array-element access to obtain a reference to a host built-in and pollute its prototype in the main n8n process (a sandbox escape), leading to a denial of service. Both self-hosted and cloud instances running the VM expression engine are affected.
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- EPSS 0.5% (30-day exploitation probability)+6
- Technical severity (high)+6
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
CISA SSVC assessment CISA
Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
- Documented mitigation — github.com (NIST National Vulnerability Database)
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (N8n N8n, N8n-io N8n).
- Apply the documented mitigations until a definitive fix is available.
- Search available logs for exploit probes matching the vulnerability class (injection), errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
Every base score collected
Sources score independently and may disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Scored by |
|---|---|---|---|---|---|
| 6.1 | CVSS 4.0 | Medium | — | — | disclosure@vulncheck.com via NIST National Vulnerability Database |
| 6.1 | CVSS 4.0 | Medium | — | — | VulnCheck via CVE Program (cve.org) e CISA ADP |
| 8.1 | CVSS 3.1 | High | 2.8 | 5.2 | nvd@nist.gov via NIST National Vulnerability Database |
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H (score shown at the top: nvd@nist.gov) Weakness MITRE
Weakness class according to MITRE’s CWE catalog.
EPSS over time FIRST
Oct 15, 2026 → Oct 16, 2026 · 2 reading(s) · max 0.51%
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
- Look for parameters with command/query metacharacters and unexpected child processes of the service.
Timeline
What happened to this CVE, newest first.
- 2026
- Affected products added · n8n-io/n8n
- SSVC assessment updated
- Record published
- Fix documented
- CVSS changed · 8.1
- Source status changed · → Analyzed
- Record created in this database
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 1× Official description updated · Oct 15, 2026 – Oct 15, 2026
References
2 on the record
Elsewhere on this site
Related CVEs (same products)
- High CVE-2026-110853 n8n before 1.123.83 Authorization Bypass via Execute Sub-workflow Inline JSON 2d
- Medium CVE-2026-110851 n8n before 2.41.4 and 2.42.1 Cross-Project Agent Ownership Transfer via Agents Create Endpoint 2d
- Medium CVE-2026-110852 n8n before 1.123.83, 2.41.4, and 2.42.1 Unauthenticated Workflow Execution via Dynamic-Path Webhook Resolution 2d
- High CVE-2026-110846 n8n before 2.41.4 and 2.42.1 Send-and-Wait HMAC Signature Bypass via Waiting-Webhook 2d
- Medium CVE-2026-110848 n8n before 1.123.83, 2.41.4, and 2.42.1 Prototype Pollution via AI Workflow Builder Connection Merge 2d
- High CVE-2026-110847 n8n before 1.123.83, 2.41.4, and 2.42.1 Stored XSS via Chat Trigger customCss Parameter 2d
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2026-72769 is "n8n before 1.123.67 Prototype Pollution via VM Expression Engine", rated High. It affects N8n (N8n); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 8.1 describes technical severity. EPSS 0.51% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
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