CVE-2026-75510 Novu: Stored XSS in In-App Inbox via notification redirect.url javascript: scheme
An attacker can inject JavaScript into notification redirects, allowing session theft and authenticated actions when users click notifications in the inbox.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2026-75510?
CVE-2026-75510 is a medium-severity cross-site scripting vulnerability in novuhq novu, published on 22 Sep 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Official description
Novu provides an API for sending notifications through multiple channels. Prior to 3.18.0, Novu's @novu/js In-App Inbox and the @novu/react Inbox component accept a notification call-to-action redirect.url from the v1 cta.data object and pass it through apps/api/src/app/inbox/utils/notification-mapper.ts and packages/js/src/ui/components/Notification/DefaultNotification.tsx to the navigate function in packages/js/src/ui/context/InboxContext.tsx without validating its URL scheme. An authenticated organization member or environment API-key holder can store a javascript: redirect with target _self in an in-app workflow. When a recipient using a Chromium-based browser clicks the notification, window.open executes the redirect in the current inbox-hosting origin, which can expose session material and permit authenticated actions in a customer application or the self-hosted Novu dashboard. This issue is fixed in version 3.18.0.
Weakness: CWE-79
Which versions are affected by CVE-2026-75510?
2 open source packages ship an affected version, including @novu/js.
| Package | Affected | Fixed in |
|---|---|---|
@novu/js npm | All versions | 3.18.0 |
@novu/js npm | All versions | 3.18.0 |
How do I fix CVE-2026-75510?
Upgrade @novu/js to 3.18.0 or later.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2026-75510 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-75510 exists.
Sources
Also known as GHSA-8gr3-5j6f-25gp.