CVE-2026-75511 Novu: Server-Side Request Forgery (SSRF) via Chat Provider Webhook URLs
An authenticated user can trigger Server-Side Request Forgery in Novu by supplying malicious chat webhook URLs, allowing access to internal network services.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-75511?
CVE-2026-75511 is a medium-severity server-side request forgery vulnerability in @novu api-service, published on 22 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
Novu provides an API for sending notifications through multiple channels. Prior to 3.18.0, Novu accepts chat webhook URLs from subscriber credentials.webhookUrl, channel endpoint endpoint.url, event payload.webhookUrl, and event overrides.webhookUrl, then passes the selected endpoint.url through send-message-chat.usecase.ts to raw HTTP requests in the Slack, Discord, Mattermost, Microsoft Teams, Grafana On-Call, Ryver, Rocket.Chat, GetStream, and Zulip providers. An authenticated user can supply an internal or otherwise restricted destination because these paths do not apply normalizeOutboundHttpUrl, assertSafeOutboundUrl, or the DNS-pinned safeOutboundJsonRequest protection used by the generic webhook providers. The Novu worker can consequently issue attacker-directed POST requests to internal network services and cause interactions or actions supported by those services. This issue is fixed in version 3.18.0.
Weakness: CWE-918
Which versions are affected by CVE-2026-75511?
How do I fix CVE-2026-75511?
No fix has been published for CVE-2026-75511 yet. Limit exposure of the affected software until one is available.
Upgrade, and send outbound requests through an allow-list that blocks internal addresses. More about Server-side request forgery.
Is CVE-2026-75511 being exploited?
There is no known exploitation of CVE-2026-75511 in the wild and no public exploit code.
Sources
Also known as GHSA-pg9q-8v57-hqph.