CVE-2026-54683 is a medium-severity (CVSS 6.5) vulnerability in nl.nl-portal:documenten-api. O3 Security confirms whether CVE-2026-54683 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
NL Portal Backend Libraries: Document contents remained downloadable by any logged-in user (incomplete fix of CVE-2026-49463)
Real-World Exposure
nl.nl-portal:documenten-apiReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Maven packages — download data is not available via public APIs for these ecosystems.
Description
Summary
A previous advisory (CVE-2026-49463 / GHSA-qpm9-h556-mwxm) reported that any logged-in user could download any document by its identifier, and stated this was fixed in 3.0.1. For the document-content part that fix was incomplete: documents remained downloadable by any authenticated user in 3.0.1 and 3.0.2, and the issue was only fully resolved in 3.0.3.
Relationship to CVE-2026-49463
This advisory is a follow-up to CVE-2026-49463. That advisory described the problem on the GraphQL getDocumentContent query and listed nl.nl-portal:documenten-api as fixed in 3.0.1. In practice:
- The 3.0.1 change added an authentication parameter to the GraphQL query but never used it, so the query kept returning any document regardless of ownership.
- The same flaw also existed on a REST endpoint that the original advisory did not cover, and that endpoint was not changed in 3.0.1 or 3.0.2.
Both were removed in 3.0.3, which is the first release where the document-content issue is actually fixed.
What was wrong
A document's contents could be fetched in two ways, and neither verified the caller's relationship to the document:
- a REST endpoint:
GET /api/documentapi/{documentapi}/document/{documentId}/content - a GraphQL query:
getDocumentContent
Being logged in was required, but that was the only check — there was no per-document authorization. (A security rule meant to guard the REST endpoint also pointed at the wrong URL and never took effect; even if it had, it would only have required a login, not ownership.)
Proof of concept
While logged in as any portal user, request a document that belongs to someone else:
GET /api/documentapi/openzaak/document/<another-users-document-id>/content
The server returns the document contents (HTTP 200), even though the caller has no relationship to that document. The getDocumentContent GraphQL query behaves the same way.
Impact
A logged-in user could read the contents of documents belonging to other people. In a citizen or business portal these documents can contain sensitive personal information. To exploit this, an attacker needs a valid login and a target document's identifier. Document identifiers are random and hard to guess, which limits — but does not prevent — abuse, since identifiers can leak through other channels.
Patches
Fixed in 3.0.3. Both the REST endpoint and the GraphQL query were removed entirely. Document contents can now only be downloaded through endpoints that first confirm the caller is allowed to see the document:
- one that requires the caller to have a role on the related case (zaak);
- one that requires the caller to own the message (bericht) the document is attached to.
If your application relied on the removed endpoints, switch to one of these case- or message-scoped download endpoints.
Workarounds
If you cannot upgrade immediately, block the path GET /api/documentapi/*/document/*/content and the getDocumentContent GraphQL query at your gateway or reverse proxy, and remove any client code that calls them. There is no setting that adds the missing per-document check in affected versions; upgrading (or removing the endpoints) is the only complete fix.
References
- Related advisory: GHSA-qpm9-h556-mwxm (CVE-2026-49463)
- Fix commits: 6e738a87 (GraphQL query removed, PR #690), e326e6db (REST endpoint removed)
- Affected module:
nl.nl-portal:documenten-api
Credits
Reported by Ray Sabee, https://whitehatsecurity.nl/ (independent security researcher). Github handle: raysabee
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | nl.nl-portal:documenten-api | all versions | 3.0.3 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for nl.nl-portal:documenten-api. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update nl.nl-portal:documenten-api to 3.0.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-54683 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2026-54683 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2026-54683. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-54683 in your dependencies?
O3 detects CVE-2026-54683 across Maven dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.