What’s Vulnerable › Vulnerabilities

CVE-2026-75511: Novu: Server-Side Request Forgery (SSRF) via Chat Provider Webhook URLs

• Severity: medium (CVSS 5.3 v4.0)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.5% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-09-22 · updated 2026-09-26
• Weakness: CWE-918

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.

Affected products

• @novu api-service: before 3.18.0
• novuhq novu: before 3.18.0

References

• https://github.com/novuhq/novu/commit/dabfd66457c0b98ad46a8186e69f74f570a990c2
• https://github.com/novuhq/novu/pull/11455
• https://github.com/novuhq/novu/releases/tag/v3.18.0
• https://github.com/novuhq/novu/security/advisories/GHSA-pg9q-8v57-hqph

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