CVE-2026-25051: n8n Improper CSP Enforcement in Webhook Responses May Allow Stored XSS
Impact
A Cross-site Scripting (XSS) vulnerability has been identified in the handling of webhook responses and related HTTP endpoints. Under certain conditions, the Content Security Policy (CSP) sandbox protection intended to isolate HTML responses may not be applied correctly.
An authenticated user with permission to create or modify workflows could abuse this to execute malicious scripts with same-origin privileges when other users interact with the crafted workflow. This could lead to session hijacking and account takeover.
Patches
The issue has been fixed in n8n versions 1.122.5 and 1.123.2. Users should upgrade to these versions or later to remediate the vulnerability.
Workarounds
If upgrading is not immediately possible, administrators should consider the following temporary mitigations:
- Limit workflow creation and editing permissions to fully trusted users only. - Never execute untrusted workflows. - Review workflows that receive data from via webhooks, forms, or MCP servers to ensure they are communicating with trusted entities before executing them manually.
These workarounds do not fully remediate the risk and should only be used as short-term mitigation measures.
--- n8n has adopted CVSS 4.0 as primary score for all security advisories. CVSS 3.1 vector strings are provided for backward compatibility.
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:N
Other sources
n8n is an open source workflow automation platform. Prior to version 1.123.2, a Cross-Site Scripting (XSS) vulnerability has been identified in the handling of webhook responses and related HTTP endpoints. Under certain conditions, the Content Security Policy (CSP) sandbox protection intended to isolate HTML responses may not be applied correctly. An authenticated user with permission to create or modify workflows could abuse this to execute malicious scripts with same-origin privileges when other users interact with the crafted workflow. This could lead to session hijacking and account takeover. This issue has been patched in version 1.123.2.
— MITRE
Affected Software
Remediation
Event History
Frequently Asked Questions
What is the severity of CVE-2026-25051?
CVE-2026-25051 is categorized as a Cross-site Scripting (XSS) vulnerability with potential for high severity in certain configurations.
How do I fix CVE-2026-25051?
To resolve CVE-2026-25051, upgrade to n8n version 1.123.2 or above, or to 1.122.5 if you are using a prior version.
What software is affected by CVE-2026-25051?
CVE-2026-25051 affects n8n versions prior to 1.123.2 and includes specific versions between 1.123.0 and 1.123.2.
What are the potential impacts of CVE-2026-25051?
The potential impacts include the ability for attackers to execute arbitrary scripts in the context of users' browsers, leading to stored XSS.
Is there a workaround for CVE-2026-25051 if I cannot upgrade?
There are no documented workarounds for CVE-2026-25051, so upgrading is strongly recommended.