CVE-2026-56356
mediumpriority · track · 0EPSS 0.003 · 16 %ileDEEUUSEPSS · scored 2026-10-27
n8n contains a stored cross-site scripting vulnerability in the Chat Trigger node's Custom CSS field due to a misconfiguration of the sanitize-html library. Affected releases are those before 1.123.27, the 2.0.0 through 2.13.2 line, and 2.14.0 (fixed in 1.123.27, 2.13.3, and 2.14.1). An authenticated user with permission to create or modify workflows can inject JavaScript that bypasses sanitization, resulting in stored XSS against any user who visits the public chat page.
cvss
Technical severity, 0–10. One row per scoring source.
base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · low–medium · 1.2–5.4
ssvc
A stakeholder decision — act, attend, or track — from exploitation and impact.
weaknesses
The CWE weakness classes this flaw belongs to.
affected products (14)
Products and version ranges known to be affected.
advisories (2)
Vendor and ecosystem advisories describing this.
- WID-SEC-W-2026-0877n8n: Mehrere SchwachstellenDeutsch2026-03-25csaf · cert_bundDE
Ein Angreifer kann mehrere Schwachstellen in n8n ausnutzen, um erweiterte Privilegien, einschließlich Administratorrechte, zu erlangen, um beliebigen Code auszuführen, Daten zu manipulieren, Sicherheitsmaßnahmen zu umgehen, vertrauliche Informationen offenzulegen oder Cross-Site- und Man-in-the-Middle-Angriffe durchzuführen.
- GHSA-3c7f-5hgj-h279n8n has XSS in Chat Trigger Node through Custom CSS2026-03-27ghsa · osvUS
## Impact An authenticated user with permission to create or modify workflows could inject malicious JavaScript into the Custom CSS field of the Chat Trigger node. Due to a misconfiguration in the `sanitize-html` library, the sanitization could be bypassed, resulting in stored XSS on the public chat page. Any user visiting the chat URL would be affected. ## Patches The issue has been fixed in n8n versions 1.123.27, 2.13.3, and 2.14.1. Users should upgrade to one of 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. - Disable the Chat Trigger node by adding `@n8n/n8n-nodes-langchain.chatTrigger` to the `NODES_EXCLUDE` environment variable. These workarounds do not fully remediate the risk and should only be used as short-term mitigation measures.
also known as (3)
Other names and identifiers for this entity.
sources
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references (6)
External citations — patches, advisories, analysis.
- https://github.com/n8n-io/n8n/security/advisories/GHSA-3c7f-5hgj-h279cnnvd
- https://www.vulncheck.com/advisories/n8n-stored-cross-site-scripting-in-chat-trigger-node-custom-css-fieldcnnvd
- https://github.com/n8n-io/n8n/security/advisories/GHSA-3c7f-5hgj-h279enisa_euvd
- https://www.vulncheck.com/advisories/n8n-stored-cross-site-scripting-in-chat-trigger-node-custom-css-fieldenisa_euvd
- https://github.com/n8n-io/n8n/security/advisories/GHSA-3c7f-5hgj-h279MitigationVendor Advisorynvd
- https://www.vulncheck.com/advisories/n8n-stored-cross-site-scripting-in-chat-trigger-node-custom-css-fieldThird Party Advisorynvd
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