NL Portal: IDOR allows any authenticated user to complete and tamper with another user's taak (CVE-2026-49464) | HOL Guard CVE

High · CVSS 8.1CVE-2026-49464GHSA-6H3C-R723-7FX3

NL Portal: IDOR allows any authenticated user to complete and tamper with another user's taak

Answer in brief

CVE-2026-49464 records a High severity (CVSS 8.1) vulnerability in NL Portal: IDOR allows any authenticated user to complete and tamper with another user's taak. The current sources do not mark it as known exploited. The current feed maps nl-portal/nl-portal-backend-libraries (generic), nl.nl-portal:taak (maven), nl.nl-portal:taak (maven). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Sep 11, 2026Updated Sep 15, 2026Source checked Sep 17, 2026First seen by HOL Jul 8, 2026Material review Sep 15, 2026

Upstream Advisory

Key facts

Risk: High · CVSS 8.1
Exploitation: Not marked as known exploited
Affected software: 3 mapped packages or products
Fix availability: Available

Why this deserves its current priority

CVSS is 8.1. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps nl-portal/nl-portal-backend-libraries (generic), nl.nl-portal:taak (maven), nl.nl-portal:taak (maven). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
nl-portal/nl-portal-backend-librariesgeneric	>= 1.5.0, < 3.0.1	Not reported
nl.nl-portal:taakmaven	>=1.5.0,<=3.0.0	3.0.1
nl.nl-portal:taakmaven	>=1.5.0 <3.0.1	3.0.1

Recommended response

Check inventory. Check lockfiles and deployed manifests for nl-portal/nl-portal-backend-libraries, nl.nl-portal:taak, nl.nl-portal:taak.
Review the reported fix. Update nl.nl-portal:taak to 3.0.1; nl.nl-portal:taak to 3.0.1 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Sep 11, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 15, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Jul 8, 2026

Sources and claim methodology

Upstream source 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

Quoted source text, attributed separately from HOL analysis.