CVE-2026-86076 json
n8n: Expression Sandbox Escape in Editor-UI Enables Stored Cross-User JavaScript Execution
published 2026-09-08 2 mo ago modified 2026-09-11 58 d ago also GHSA-hw8v-xxg5-vvvx , EUVD-2026-74280
- cvss
- 8.8
- version 3.1, NVD
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.7%
- EPSS 0.7% chance of exploitation in 30 days, percentile 51%
- public exploits
- 0
- none known
Summary
n8n is an open source workflow automation platform. Prior to 1.123.76, 2.37.7, and 2.38.2, the expression compiler sanitizer resolved through dynamically scoped this and did not reject reserved class member names. A class field named __sanitize could rebind the sanitizer and reach the Function constructor, enabling backend code execution and editor-preview JavaScript execution. The affected AST hook is PrototypeSanitizer in packages/workflow/src/expression-sandboxing.ts. This issue is fixed in versions 1.123.76, 2.37.7 and 2.38.2.
Patch / fix
- npm n8n 1.123.76, 2.37.7, 2.38.2
- n8n n8n 1.123.76, 2.37.7, 2.38.2
CISA SSVC
- Exploitation
- none
- Automatable
- no
- Technical impact
- total
- Assessed
- 1 mo ago
Exploit prediction
0.65% chance of exploitation in the next 30 days, higher than 51% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 4.0 | 8.7 | CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:N/SA:N |
| CNA | 4.0 | 8.7 | CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/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 |
| NVD | 3.1 | 8.8 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| npm | n8n | <1.123.76 >=2.38.0, <2.38.2 >=2.0.0, <2.37.7 |
1.123.76 2.38.2 2.37.7 |
Affected products
- n8n-io n8n
Classification
- Weakness
-
- CWE-94 Improper Control of Generation of Code
References
-
github.com
/n8n-io/n8n/security/advisories/GHSA-hw8v-xxg5-vvvx
web, mitigation, vendor-advisory
-
github.com
/n8n-io/n8n/releases/tag/n8n@1.123.76
web, release-notes
-
github.com
/n8n-io/n8n/releases/tag/n8n@2.37.7
web, release-notes
-
github.com
/n8n-io/n8n/releases/tag/n8n@2.38.2
web, release-notes
-
nvd.nist.gov
/vuln/detail/CVE-2026-86076
advisory
-
github.com
/n8n-io/n8n
package
Sources
- CVE List CVE-2026-86076
- GitHub Advisory GHSA-hw8v-xxg5-vvvx
- NVD CVE-2026-86076
Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.