Auth bypass in Nl-Portal Nl-Portal-Backend-Libraries
CVE-2026-49464
NL Portal Backend Libraries provide backend components for Dutch government portals that interact with residents, customers, suppliers, and partner organizations. The `nl.nl-portal:taak` package from version 1.5.0 through 3.0.0 fails to verify ownership when processing the `submitTaakV2` GraphQL mutation, allowing an authenticated user who knows or guesses another user’s task ID to read its form data, overwrite its submitted data, and mark the task as completed. Version 3.0.1 contains a patch. As a workaround, block the `submitTaakV2` mutation at the API gateway or restrict the `/graphql` endpoint to trusted networks
Vulnerability class: IDOR (Insecure Direct Object Reference)
CVSS v3 metric
CVSS v3 base score 8.1 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N.
Affected products
- Nl-portal Nl-portal-backend-libraries — versions >= 1.5.0, < 3.0.1
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM)
Frequently asked questions
- What is CVE-2026-49464?
- CVE-2026-49464 is a high-severity vulnerability in Nl-Portal Nl-Portal-Backend-Libraries, classified under Authorization Bypass Through User-Controlled Key. CVSS score: 8.1/10. Published 2026-09-11.
- How severe is CVE-2026-49464?
- High severity. CVSS v3 base score is 8.1 out of 10.