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

1. In CISA KEV: not seen
2. Exploited (reported): not seen
3. Scanning observed: not seen
4. Proof of concept public: not seen
5. Not establishedNothing in the sources we check

DescriptionNVD

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.

Exploitation

Check available, not yet exploited. A public nuclei template can confirm it on a system you are authorised to test.

CISA KEV

Not listed

Public check

Hoppscotch <= 2026.4.1 - Mass Assignment JWT_SECRET Overwrite · nuclei template in projectdiscovery/nuclei-templates

Weakness

Improperly Controlled Modification of Dynamically-Determined Object Attributes · Deserialization and Object Injection

Vendor

hoppscotch

Published

July 2026

Band

Check available, not yet exploited, July 2026

• NVD entrynvd.nist.gov
• Vendor advisorygithub.com
• CVE recordcve.org
• Weakness CWE-915cwe.mitre.org