GHSA-vg6v-j97m-h5xq

@novu/application-generic: `validateUrlSsrf` permits CGNAT (100.64.0.0/10) destinations — affects Workflow HTTP request step + Webhook filter condition

Published

2026-07-28

Modified

2026-07-28

Sources

github-advisory

Summary

Hi Novu team, Reporting an SSRF blocklist gap in the shared `validateUrlSsrf` guard. A complete self-contained reproduction is inlined below — copy the four files into a directory and run `docker compose up`, plus a single-file probe that runs against Node directly. Locally validated against HEAD `291817c`. ## Summary Novu's shared SSRF guard `validateUrlSsrf(url)` is used before server-side requests to user-configured URLs. The guard resolves hostnames and blocks a regex list of private/reserved IP ranges, but it does not block `100.64.0.0/10` shared address space. As a result, Novu features protected by this guard can still send server-side requests to destinations such as `100.100.100.200` (Alibaba Cloud metadata service) and any other service reachable in `100.64.0.0/10`. ## Affected code Guard: - `libs/application-generic/src/utils/ssrf-url-validation.ts` - `isPrivateIp(...)` regex list at lines 9-28 - DNS resolution and address validation at lines 55-72 Product call-sites: - Workflow HTTP request step: `apps/worker/src/app/workflow/usecases/send-message/execute-http-request-step.usecase.ts` — calls `validateUrlSsrf(url)` at line 149, then uses `HttpClientService` to send the request. - Webhook filter condition: `libs/application-generic/src/usecases/conditions-filter/conditions-filter.usecase.ts` — calls `validateUrlSsrf(child.webhookUrl)` at line 265, then sends `axios.post(child.webhookUrl, ...)` at line 277. HTTP client: - `libs/application-generic/src/services/http-client/http-client.service.ts` — uses `got(gotOptions)` at lines 120 and 142 after the preflight validation. ## Root cause The SSRF guard uses a hand-written regex deny-list: ```ts /^0\.0\.0\.0$/i, /^127\./, /^10\./, /^172\.(1[6-9]|2[0-9]|3[01])\./, /^192\.168\./, /^169\.254\./, /^::ffff:127\./i, /^::ffff:10\./i, /^::ffff:172\.(1[6-9]|2[0-9]|3[01])\./i, /^::ffff:192\.168\./i, /^::ffff:169\.254\./i, /^::1$/, /^fc00:/i, /^fe80:/i, ``` This list omits `100.64.0.0/10`, also called shared address space or CGNAT. These addresses are not RFC1918 private addresses, but they are also not normal public-internet destinations. Cloud and infrastructure providers commonly use special-use address ranges for metadata and internal services; **Alibaba Cloud metadata is available at `100.100.100.200`**. ## Reproduction — Part 1: unit-level probe (no Docker required) Save the following file and run with `node novu_ssrf_guard_probe.js`. The script replicates `validateUrlSsrf` from `libs/application-generic/src/utils/ssrf-url-validation.ts` **verbatim** (the `isPrivateIp` regex list is copied as-is) and tests several URL categories. ### `novu_ssrf_guard_probe.js` ```javascript const dns = require('dns/promises'); function isPrivateIp(ip) { const privateRanges = [ /^0\.0\.0\.0$/i, /^127\./, /^10\./, /^172\.(1[6-9]|2[0-9]|3[01])\./, /^192\.168\./, /^169\.254\./, /^::ffff:127\./i, /^::ffff:10\./i, /^::ffff:172\.(1[6-9]|2[0-9]|3[01])\./i, /^::ffff:192\.168\./i, /^::ffff:169\.254\./i, /^::1$/, /^fc00:/i, /^fe80:/i, ]; return privateRanges.some((range) => range.test(ip)); } async function validateUrlSsrf(url) { let parsed; try { parsed = new URL(url); } catch { return 'Invalid URL format.'; } if (parsed.protocol !== 'http:' && parsed.protocol !== 'https:') { return `URL scheme "${parsed.protocol}" is not allowed.`; } const hostname = parsed.hostname.toLowerCase(); const blockedHostnames = ['localhost', 'metadata.google.internal']; if (blockedHostnames.includes(hostname)) { return `Requests to "${hostname}" are not allowed.`; } let addresses; try { addresses = await dns.lookup(hostname, { all: true }); } catch { return `Unable to resolve hostname "${hostname}".`; } for (const { address } of addresses) { if (isPrivateIp(address)) { return `Requests to private or reserved IP addresses are not allowed (resolved: ${address}).`; } } r

Affected packages

Remediation: Upgrade to 3.17.0 or later.

References

• https://github.com/advisories/GHSA-vg6v-j97m-h5xq