CVE-2026-50160 PoC — Mass Assignment via Onboarding Endpoint Allows Unauthenticated JWT_SECRET Overwrite

Source

https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2026/CVE-2026-50160.yaml

Associated Vulnerability

Title: Mass Assignment via Onboarding Endpoint Allows Unauthenticated JWT_SECRET Overwrite (CVE-2026-50160)
Description:Hoppscotch is an API development ecosystem. In self-hosted deployments of hoppscotch-backend from version 2026.4.1 and earlier, the unauthenticated POST /v1/onboarding/config endpoint is vulnerable to mass assignment. The global NestJS ValidationPipe is configured without whitelist: true, so extra properties on the request body that are not declared in SaveOnboardingConfigRequest are not stripped and are iterated in the service layer as if they were legitimate InfraConfig entries. Because keys such as JWT_SECRET and SESSION_SECRET are valid InfraConfigEnum values and are not explicitly rejected during validation, an unauthenticated attacker who can reach a fresh instance before onboarding completes (or when no users exist) can overwrite these values in the database. Overwriting JWT_SECRET gives the attacker control of the JWT signing key, allowing them to forge tokens for any user, including administrators, and results in full server compromise. The issue is fixed in hoppscotch 2026.5.0.

Description

Hoppscotch self-hosted backend <= 2026.4.1 contains a broken authentication caused by mass assignment via unauthenticated POST /v1/onboarding/config endpoint, letting unauthenticated attackers overwrite JWT_SECRET to forge tokens and fully compromise the server, exploit requires attacker to access fresh instance before onboarding completes or when no users exist.

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