GHSA-jr45-52cw-69h5 NL Portal Backend Libraries: Document contents remained downloadable by any logged-in user (incomplete fix of CVE-2026-49463)
SummaryA 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-2026-49463This 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 wrongA 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 conceptWhile logged in as any portal user, request a document that belongs to someone else: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.ImpactA 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.PatchesFixed 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.WorkaroundsIf 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.ReferencesRelated 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`CreditsReported by Ray Sabee, https://whitehatsecurity.nl/ (independent security researcher). Github handle: [raysabee](https://github.com/raysabee)
CVSS v3.1 score: 6.5