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Novu has SSRF via conditions filter webhook bypasses validateUrlSsrf() protection

Exploited
No known exploitation
Fix
Fixed in 3.15.0
Who is exposed
Not reported

Do first: Upgrade to a fixed version: 3.15.0.

Published
Last modified
Reference
Last checked
19/100 · provisional
28% of @novu/api downloads last week were affected versions (55.6K).npm, 197.3K downloads in the last 7 days, read Nov 9, 2026
High (ghsa)
None on Exploit-DB, Metasploit or GitHub

Summary

Novu, a notification platform, has a server-side request forgery flaw in its conditions filter webhook, which sends POST requests to user-configured URLs without the private-address checks that its HTTP Request workflow step applies. An attacker who can set a condition's webhook URL could make the server send requests to internal services, and the response data can be read back through the execution details API, which may expose items such as cloud instance credentials.

Written by anthropic/claude-haiku-5.5 from the sources below. Verify against them.

Read the original description

The conditions filter webhook at libs/application-generic/src/usecases/conditions-filter/conditions-filter.usecase.ts line 261 sends POST requests to user-configured URLs using raw axios.post() with no SSRF validation. The HTTP Request workflow step in the same codebase correctly uses validateUrlSsrf() which blocks private IP ranges. The conditions webhook was not included in this protection.

Root Cause

conditions-filter.usecase.ts line 261:

return await axios.post(child.webhookUrl, payload, config).then((response) => {
  return response.data as Record<string, unknown>;
});

No call to validateUrlSsrf(). The webhookUrl comes from the workflow condition configuration with zero validation.

Protected Code (for contrast)

execute-http-request-step.usecase.ts line 130:

const ssrfValidationError = await validateUrlSsrf(url);
if (ssrfValidationError) {
  // blocked
}

This function resolves DNS and checks against private ranges (127.0.0.0/8, 10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16, 169.254.0.0/16). It exists in the codebase but is not applied to the conditions webhook path.

Proof of Concept

  1. Create a workflow with a condition step
  2. Configure the condition's webhook URL to http://169.254.169.254/latest/meta-data/iam/security-credentials/
  3. Trigger the workflow by sending a notification event
  4. The worker evaluates the condition and calls axios.post() to the metadata endpoint
  5. The response data is stored in execution details and accessible via the execution details API

Impact

Full-read SSRF. The response body is returned as Record<string, unknown> for condition evaluation and stored in the execution details raw field. The GET /execution-details API returns this data.

The POST method limits some metadata endpoints (GCP requires GET, Azure requires GET), but AWS IMDSv1 accepts POST and returns credentials. Internal services accepting POST are also reachable.

Suggested Fix

Extract validateUrlSsrf() to a shared utility and call it before the axios.post in conditions-filter.usecase.ts:

const ssrfError = await validateUrlSsrf(child.webhookUrl);
if (ssrfError) {
  throw new Error('Webhook URL blocked by SSRF protection');
}
return await axios.post(child.webhookUrl, payload, config)...

cve.now Index

19Pcve.now Index 19 of 100 · methodology v3 · provisional
  • Exploitation?/40Unknown. No CISA SSVC exploitation rating yet
  • Exposure?/25Unknown. No advisory context yet
  • Reach12/20@novu/api: 191.3K downloads a week
  • Severity7/10Rated high by ghsa
  • No patch0/5No signal

What would change the score

  • Would score about 74 if added to CISA KEV
  • Would score about 69 if CISA's SSVC rates exploitation active
  • Would score about 41 if advisories confirm default setups are exposed

Impact

  • Widely used

    @novu/api has 191.3k weekly downloads.Source: npmjs.com

    2 packages depend on @novu/api.Source: deps.dev

What to do

  • Upgrade to a fixed version: 3.15.0.

Check your systems with an agent

Paste this into a coding or ops agent. It checks your systems read-only and reports a table per asset.

Check whether my systems are affected by GHSA-4X48-CGF9-Q33F (Novu has SSRF via conditions filter webhook bypasses validateUrlSsrf() protection), using the cve.now data below.

Rules: work read-only. Do not run exploit code, proof-of-concept scripts or scanners that send attack payloads, and do not change any configuration, package, image or deployment. Report findings only.

What cve.now has for GHSA-4X48-CGF9-Q33F (entry last updated 2026-04-14):
Affected:
- npm package @novu/api: fixed in 3.15.0
Fixed versions: 3.15.0.
Setup: unknown whether the bug needs a non-default feature or setting. Check the advisory.
CISA KEV: GHSA-4X48-CGF9-Q33F is not listed as of cve.now's last read.
This KEV status is for GHSA-4X48-CGF9-Q33F only. If you also check another CVE, look up its own KEV status; never assume it from this one.

How to check:
- Packages (npm): find every lockfile in each project and run check_stack from the cve.now MCP server on each one. Compare the resolved versions, not the ranges a manifest declares, with the affected versions above. Include transitive dependencies.

Verify against the linked advisories before concluding, and cite the date you read each one:
- https://github.com/novuhq/novu/security/advisories/GHSA-4x48-cgf9-q33f
- https://github.com/novuhq/novu/commit/87d965eb88340ac7cd262dd52c8015acd092dc68
- https://github.com/novuhq/novu
Do not conclude an asset is unaffected unless you checked it and the evidence covers both its version and the conditions above. If you could not check something, mark it unknown and say what is missing.

Report a table with one row per asset and these columns: Asset | Version or build | Status (affected, fixed, not applicable, unknown) | Compensating controls | Exposure (internet-facing, internal, none) | Evidence | Next action.

Entry: https://cve.now/GHSA-4X48-CGF9-Q33F
For follow-up questions, use the cve.now MCP server at https://mcp.cve.now/mcp (no authentication), for example get_vulnerability with id GHSA-4X48-CGF9-Q33F.

Timeline

  1. Advisory published
  2. Record last updated

Affected versions

  • fixed in 3.15.0

    Fixed in 3.15.0 (released Apr 13, 2026, 1 day before disclosure).

    The latest release, 3.19.1, is not affected.

Evidence 3

Vendor advisory · 1

Establishes: Affected and fixed versions.

  1. Advisory

Other links · 2

  1. Repository
  2. Repository

Corrections

None so far.

Something wrong on this page? Report an error. Every fix is listed here.

Questions about GHSA-4X48-CGF9-Q33F

Is GHSA-4X48-CGF9-Q33F being exploited?

It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.Source: cve.now feed data

Which versions are affected by GHSA-4X48-CGF9-Q33F?

@novu/api (npm): before 3.15.0.Source: cve.now feed data

How do I fix GHSA-4X48-CGF9-Q33F?

Upgrade to a fixed version: 3.15.0.Source: cve.now feed data