Vulnerability · Published Sep 11, 2026 · Assigned by GitHub_M
CVE-2026-49464NL Portal: IDOR allows any authenticated user to complete and tamper with another user's taak
High 8.1
In plain English
A high-severity authorization bypass via user-controlled key in nl-portal-backend-libraries from nl-portal. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 29% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
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
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Maven | nl.nl-portal:taak | 3.0.1 | GHSA-6h3c-r723-7fx3 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| nl-portal | nl-portal-backend-libraries | >= 1.5.0, < 3.0.1 |
Weakness: CWE-639 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N