High

Stored XSS in n8n webhook and HTTP endpoint responses

IdentifiersCVE-2026-25051CWE-79· Improper Neutralization of Input…

CVE-2026-25051 is a cross-site scripting vulnerability in n8n, the open source workflow automation platform, affecting versions prior to 1.123.2, with advisory data also indicating fixed releases 1.122.5 and 1.123.2. The flaw is in the handling of webhook responses and related HTTP endpoints: under certain conditions, the Content Security Policy sandbox intended to isolate HTML responses is not applied correctly. As a result, an authenticated user who can create or modify workflows can craft a workflow that returns attacker-controlled HTML/script content, which may then execute with same-origin privileges when another user interacts with the workflow or its associated endpoint. The issue is effectively a stored XSS condition in workflow-driven webhook/HTTP response handling.

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ANALYST BRIEF

Impact, mitigation & remediation

What it means. What to do now. Patch path, mitigations, and the assume-compromise checklist.

Impact

What an attacker gets, and what they’ve been doing with it.

Successful exploitation allows attacker-supplied JavaScript to execute in another user's browser in the n8n application origin. Because the script runs with same-origin privileges, impact can include session hijacking, theft of authenticated session data, execution of actions as the victim user, and account takeover. The available sources specifically identify session hijacking and account takeover as primary outcomes.

Mitigation

If you can’t patch tonight, do this now.

If immediate patching is not possible, restrict workflow creation and editing permissions to fully trusted users only. Do not execute or expose untrusted workflows. Review workflows that receive data via webhooks, forms, or MCP servers, and ensure they only interact with trusted entities before manual execution. These are temporary risk-reduction measures and do not fully eliminate the vulnerability.

Remediation

Patch, then assume compromise.

Upgrade n8n to a fixed version. The provided content states the issue is patched in 1.123.2, and the advisory data specifies fixed releases 1.122.5 and 1.123.2 or later, indicating affected supported branches should be updated to at least those versions. Apply the vendor patch that corrects CSP sandbox enforcement for webhook responses and related HTTP endpoints.

PUBLIC EXPLOITS

Exploits

No public exploits tracked yet. Mallory keeps watching.

VALID 0 / 0 TOTALView more in app

No public exploit code observed for this vulnerability.

EXPOSURE SURFACE

Affected products & vendors

Products and vendors Mallory has correlated with this vulnerability. Open in Mallory to drill down to specific CPE configurations and version ranges.

VendorProductType

N8nN8napplication

Vendor-confirmed product mapping. Mallory continuously reconciles this list against your asset inventory.

ACTIVITY FEED

Recent activity

6 sources tracked across advisories, community write-ups, and news. New activity surfaces here as Mallory finds it.

6 SOURCESView more in app

upwind blogNews

Feb 5, 2026

Six n8n CVEs Disclosed in One Day Expose Workflow Security Risks - Upwind

A high-severity XSS vulnerability in n8n webhook responses/related endpoints where CSP sandbox protections are inconsistently applied, enabling authenticated workflow editors to run scripts in other users’ sessions.

the hacker newsNews

Feb 5, 2026

Critical n8n Flaw CVE-2026-25049 Enables System Command Execution via Malicious Workflows

Authenticated XSS in n8n webhook response/HTTP endpoint handling enabling same-origin script execution and potential session hijack/account takeover.

the hacker newsNews

Feb 5, 2026

Critical n8n Flaw CVE-2026-25049 Enables System Command Execution via Malicious Workflows

Authenticated workflow-author XSS via webhook responses/HTTP endpoints in n8n, enabling same-origin script execution against other users and potential session hijack/account takeover.

cvefeed high severityNews

Feb 4, 2026

CVE-2026-25051 - n8n Improper CSP Enforcement in Webhook Responses May Allow Stored XSS

An authenticated XSS issue in n8n where CSP sandboxing for certain HTML webhook/HTTP responses may not be applied correctly, enabling same-origin script execution when other users interact with a crafted workflow, potentially leading to session hijacking/account takeover.

What this page doesn’t show

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Exposure mapping

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Threat actor evidence

Every observed campaign linking this CVE to a named adversary.

Associated malware

Malware families riding this exploit, with evidence and IOCs.

Detection signatures

YARA, Sigma, Snort, and vendor rules, auto-deployed to your SIEM.

Vendor-by-vendor mapping

Cross-references every affected SKU, including bundled OEM variants.

Social activity1