# CVE-2026-59259: n8n - Permission Bypass via Expression Parser Mismatch in External Secrets

> CVE-2026-59259: n8n - Permission Bypass via Expression Parser Mismatch in External Secrets. CVSS 6.5 (CVSS 3.1).

Canonical: https://rewindex.com/cve/CVE-2026-59259
Last updated: 2026-10-24T21:10:00Z

- Published: 2026-07-15 11:25 UTC · Updated: 2026-10-24 21:10 UTC · Assigner: VulnCheck
- CVSS: 6.5 (CVSS 3.1) · Severity: Medium · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
- EPSS: 0.44%, 38th percentile (scored 2026-10-25)
- CISA KEV: no
- CWE: CWE-639

## Description

n8n before versions 1.123.61, 2.27.4, and 2.28.1 contains a permission bypass vulnerability in external secrets handling caused by a mismatch between the static validation check and the runtime expression engine. An authenticated user with credential create or update permissions but without the externalSecret:list scope can embed external secret references into credentials in forms the static validation does not detect; these references resolve at workflow execution time, exposing secret values the user is not authorized to access. This issue only affects instances where an external secrets provider is configured and Advanced Permissions are in use.

## Affected vendors and products

- n8n: n8n

## Tracked companies

- [n8n](https://rewindex.com/company/n8n.md)

## References

- [CVE record on cve.org](https://www.cve.org/CVERecord?id=CVE-2026-59259)
- [NVD entry](https://nvd.nist.gov/vuln/detail/CVE-2026-59259)
- [https://github.com/n8n-io/n8n/security/advisories/GHSA-jp7m-xcgx-57qm](https://github.com/n8n-io/n8n/security/advisories/GHSA-jp7m-xcgx-57qm)
- [https://www.vulncheck.com/advisories/n8n-permission-bypass-via-expression-parser-mismatch-in-external-secrets](https://www.vulncheck.com/advisories/n8n-permission-bypass-via-expression-parser-mismatch-in-external-secrets)

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_Sources: CVE records from the CVE Program (cve.org). CVE® is a registered trademark of The MITRE Corporation. (https://www.cve.org/) This product uses data from the NVD API but is not endorsed or certified by the NVD. (https://nvd.nist.gov/) Known Exploited Vulnerabilities catalog from CISA. (https://www.cisa.gov/known-exploited-vulnerabilities-catalog) EPSS scores from FIRST (Exploit Prediction Scoring System). (https://www.first.org/epss/)_


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Canonical: https://rewindex.com/cve/CVE-2026-59259 · Markdown: https://rewindex.com/cve/CVE-2026-59259.md · JSON: https://rewindex.com/api/v1/cves/CVE-2026-59259 · Data licensed CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/) · Generated 2026-10-26T03:11:13.992Z