Vulnerabilities in pkg:npm/@novu/js
PACKAGECVE-2026-75510 is a MODERATE cross-site scripting vulnerability (CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')) affecting Novu libraries in the npm ecosystem. The issue involves stored xss in in-app inbox via notification redirect.url javascript: scheme. Remediation is available by upgrading affected packages to version 3.18.0.
pkg:npm/@novu/js
Vulnerability advisories affecting package pkg:npm/@novu/js. Select an advisory below to view technical details or fixes.
| Advisory ID | CVE / NVD | Severity | Summary |
|---|---|---|---|
| GHSA-8gr3-5j6f-25gp | CVE-2026-75510 | MODERATE | Novu: Stored XSS in In-App Inbox via notification redirect.url javascript: scheme |
CVE-2026-75510 at a Glance
How to Fix CVE-2026-75510
To remediate this vulnerability, upgrade all affected Novu dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.
npm install @novu/js@3.18.0
Run the following command in your project directory to verify that all resolved dependencies use the patched release:
npm ls @novu/js
How to Check if You Are Affected
To determine whether your Node.js application is affected by CVE-2026-75510, inspect your project dependencies using npm:
npm ls @novu/js
Analyze the terminal output to locate any version of Novu in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 3.18.0), your application is affected.
Note: The npm ls @novu/js command inspects dependencies declared in your package.json and lockfile; it does not perform automated runtime dynamic scanning.
Technical Details
Vulnerability Mechanism & Technical Analysis
This vulnerability is classified under CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting'), where the product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users. In Novu, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.
Source Advisory Statement
CVE-2026-75510 Affected Novu Versions
1 component(s)| Product / Package | Ecosystem | Affected Versions | Fixed Version |
|---|---|---|---|
|
@novu/js
|
npm |
< 3.18.0
|
3.18.0
|
References
Frequently Asked Questions
What is CVE-2026-75510?
Which Novu versions are affected?
What version fixes CVE-2026-75510?
Is @novu/js affected?
What CWE is associated with CVE-2026-75510?
How can I check npm dependencies for CVE-2026-75510?
Machine-readable OSV JSON
OSV v1.5 Schema
{
"schema_version" : "1.4.0",
"id" : "GHSA-8gr3-5j6f-25gp",
"modified" : "2026-09-22T20:34:35Z",
"published" : "2026-09-22T20:34:35Z",
"aliases" : [ "CVE-2026-75510" ],
"summary" : "Novu: Stored XSS in In-App Inbox via notification redirect.url javascript: scheme",
"details" : "## Summary\n\nThe `@novu/js` In-App Inbox renderer passes a notification's `redirect.url` to `window.open()` with no URL-scheme validation. The value originates from a notification's call-to-action and is delivered to the recipient verbatim.\n\nAn authenticated organization member (or any holder of the environment API key) creates a v1 in-app workflow whose step CTA stores `cta.data = { url: \"javascript:<payload>\", target: \"_self\" }`. The v1 message-template `cta.data` field is a Mongoose `Mixed` type, so the arbitrary `target` key is accepted and persisted. The server-side inbox mapper copies `cta.data.url` and `cta.data.target` into the notification's `redirect` object with no scheme check. Novu's v2 control schema validates redirect URLs against `redirectUrlRegex` (which rejects `javascript:`), proving the intended invariant; the v1 path and the client renderer do not enforce it.\n\nWhen the recipient clicks the notification, the inbox calls `window.open(url, \"_self\", \"noopener noreferrer\")`. In Chromium browsers a `javascript:` URL opened with `target=\"_self\"` executes in the current document origin (the default `_blank` is browser-blocked, so the attacker sets `_self`).\n\nResult: a low-privilege content author runs arbitrary JavaScript in the browser of every recipient who clicks, in the origin that hosts the inbox (the customer application or the self-hosted Novu dashboard, neither of which sends a CSP).\n\n## Affected\n\nnovuhq/novu self-hosted and cloud, API <= v3.15.0; `@novu/js` <= 3.15.0 and `@novu/react` (Inbox component). Confirmed live-exploitable on v3.15.0 (Docker community compose, default config, default roles).\nCondition: an in-app (Inbox) channel is in use, the standard product configuration.\nRecipient must use a Chromium-based browser (Chrome, Edge); the `javascript:` execution does not occur where the browser blocks `javascript:` in `window.open`.\n\n## Root cause\n\npackages/js/src/ui/context/InboxContext.tsx:108: `window.open(url, target ?? DEFAULT_TARGET, DEFAULT_REFERRER)` is reached for any URL not starting with `/`, with no scheme allowlist, so `javascript:` is passed through.\npackages/js/src/ui/components/Notification/DefaultNotification.tsx:103: the notification click handler calls `navigate(redirect.url, redirect.target)`, feeding the stored values into the sink.\napps/api/src/app/inbox/utils/notification-mapper.ts:85-89: maps `cta.data.url` and `cta.data.target` into `redirect` with no validation of either field.\nlibs/dal/src/repositories/message-template/message-template.schema.ts:41: `data: Schema.Types.Mixed` accepts the arbitrary `target` key (not present in the typed interface).\nlibs/application-generic/src/usecases/compile-in-app-template/compile-in-app-template.usecase.ts:35-36: the v1 render path handlebars-compiles `cta.data.url` and performs no scheme check.\nlibs/application-generic/src/schemas/control/in-app-control.schema.ts:24-27: the v2 control schema enforces `url: z.string().regex(redirectUrlRegex)` which rejects `javascript:`, the guard absent from the v1 path and the renderer.\n\n## Reproduction\n\nnovuhq/novu v3.15.0 Docker community compose, default config. Attacker holds an environment API key (or a member session); victim opens the inbox in Chromium.\n\n1. Create a v1 in-app workflow with a redirect CTA carrying a `javascript:` URL and `target=_self`:\n```\nPOST /v1/workflows Authorization: ApiKey <key>\n{\"name\":\"poc\",\"notificationGroupId\":\"<ng>\",\"active\":true,\n \"steps\":[{\"template\":{\"type\":\"in_app\",\"content\":\"click me\",\n \"cta\":{\"type\":\"redirect\",\"data\":{\n \"url\":\"javascript:window.top.__X=document.domain;void 0\",\"target\":\"_self\"}}}}]}\n```\n2. Trigger it to a subscriber, then read the feed with a subscriber token minted from the public application identifier (no secret):\n```\nPOST /v1/inbox/session {\"applicationIdentifier\":\"<appId>\",\"subscriberId\":\"<sub>\"}\nGET /v1/inbox/notifications Authorization: Bearer <subscriber-jwt>\n-> redirect: {\"url\":\"javascript:window.top.__X=document.domain;void 0\",\"target\":\"_self\"}\n```\n3. The subscriber clicks the notification in the `@novu/js` / `@novu/react` Inbox.\n\nLive-verified: the stored `javascript:` URL is returned verbatim by the inbox feed, and the exact shipped `navigate()` logic invoked from a real click runs `window.open(url,\"_self\",...)`, executing the payload in the `http://<dashboard>:4000` origin (no CSP); `window.top.__X` was set to the page origin. On the self-hosted dashboard the test inbox bell uses `subscriberId = user.externalId` (apps/dashboard/src/components/inbox-button.tsx:102), so a member targets another member's id and the executing payload reads `localStorage['self-hosted-jwt']` (apps/dashboard/src/utils/self-hosted/jwt-manager.tsx:4), the dashboard session token.\n\n## Impact\n\n- Stored XSS in the recipient's browser, cross-principal (content author to end-user subscriber), persistent, replicated to every recipient of the workflow.\n- On the self-hosted dashboard origin (no CSP), theft of `localStorage['self-hosted-jwt']` yields takeover of another member or admin account.\n- In a customer application embedding the inbox, session and token theft and authenticated actions in that origin.\n- Triggered by the lowest privilege that can author a workflow, default config, one recipient click.\n\n## Credit\n\nJan Kahmen, [turingpoint](https://turingpoint.de) (jan@turingpoint.de)",
"severity" : [ {
"type" : "CVSS_V4",
"score" : "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N"
} ],
"affected" : [ {
"package" : {
"ecosystem" : "npm",
"name" : "@novu/js"
},
"ranges" : [ {
"type" : "ECOSYSTEM",
"events" : [ {
"introduced" : "0"
}, {
"fixed" : "3.18.0"
} ]
} ],
"database_specific" : {
"last_known_affected_version_range" : "<= 3.17.0"
}
} ],
"references" : [ {
"type" : "WEB",
"url" : "https://github.com/novuhq/novu/security/advisories/GHSA-8gr3-5j6f-25gp"
}, {
"type" : "ADVISORY",
"url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-75510"
}, {
"type" : "WEB",
"url" : "https://github.com/novuhq/novu/pull/11453"
}, {
"type" : "WEB",
"url" : "https://github.com/novuhq/novu/commit/f105f3d41a4405a75f803634d49f15a967524d8a"
}, {
"type" : "PACKAGE",
"url" : "https://github.com/novuhq/novu"
}, {
"type" : "WEB",
"url" : "https://github.com/novuhq/novu/releases/tag/v3.18.0"
} ],
"database_specific" : {
"cwe_ids" : [ "CWE-79" ],
"severity" : "MODERATE",
"github_reviewed" : true,
"github_reviewed_at" : "2026-09-22T20:34:35Z",
"nvd_published_at" : "2026-09-22T16:17:53Z"
}
}