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

Medium · CVSS 5.3CVE-2026-75511

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

Answer in brief

CVE-2026-75511 records a Medium severity (CVSS 5.3) vulnerability in Novu: Server-Side Request Forgery (SSRF) via Chat Provider Webhook URLs. The current sources do not mark it as known exploited. The current feed maps @novu/api-service (generic), novuhq/novu (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Sep 22, 2026Updated Sep 22, 2026Source checked Sep 22, 2026First seen by HOL Sep 22, 2026Material review Sep 22, 2026

Upstream Advisory

Key facts

Risk: Medium · CVSS 5.3
Exploitation: Not marked as known exploited
Affected software: 2 mapped packages or products
Fix availability: Available

Why this deserves its current priority

CVSS is 5.3. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps @novu/api-service (generic), novuhq/novu (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
@novu/api-servicegeneric	<3.18.0	3.18.0
novuhq/novugeneric	<3.18.0	3.18.0

Recommended response

Check inventory. Check lockfiles and deployed manifests for @novu/api-service, novuhq/novu.
Review the reported fix. Update @novu/api-service to 3.18.0; novuhq/novu to 3.18.0 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Sep 22, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 22, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Sep 22, 2026

Sources and claim methodology

Upstream source 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.

Quoted source text, attributed separately from HOL analysis.