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GHSA-vg6v-j97m-h5xq: @novu/application-generic: `validateUrlSsrf` permits CGNAT (100.64.0.0/10) destinations — affects Workflow HTTP request step + Webhook filter condition

mediumCVSS 6.8
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: /^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 RFC1

Details

Source
GitHub Security Advisories (INTL · database · site)
Severity
medium — CVSS 6.8
Published
2026-07-28
Last updated
2026-07-28
Exploitation
Not in CISA KEV at last sync

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

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