---
id: "CVE-2026-104189"
kind: "vulnerability"
aliases: ["CVE-2026-104189"]
title: "Nextcloud 3D Viewer: password-protected shares readable by token alone"
severity: "high"
cvss: 7.5
epss: null
exploited: false
status: "open"
category: "package"
products: []
ecosystems: []
tags: ["3d-viewer", "nextcloud", "package", "self-hosted"]
not_affected_if: ["app-not-installed", "no-3d-files-in-shares", "version-3.3.2-or-later"]
published_at: "2026-10-27T16:17:28+00:00"
first_seen_at: "2026-10-27T16:33:06+00:00"
updated_at: "2026-10-27T16:34:15+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-104189", "first_seen_at": "2026-10-27T16:33:06+00:00"}]
---

# Nextcloud 3D Viewer: password-protected shares readable by token alone

The 3D Viewer app for Nextcloud exposes a public file endpoint that skips share authorization, so anyone holding a share token can download 3D model files even when the share is password-protected. An attacker gets the full contents of those files with no password and no session.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- Run `occ app:list` on the Nextcloud server and look for `threedviewer` with a version between `1.7.9` and `3.3.1`
- Check whether the app is installed and enabled at all with `occ app:info threedviewer`

## Fix

- Upgrade the 3D Viewer for Nextcloud app to `3.3.2` or later
- Until upgraded, disable the app with `occ app:disable threedviewer`, or stop relying on passwords to protect link shares that contain 3D model files

## Timeline

- 2026-10-27T16:33:06+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-104189

## From the sources

The 3D Viewer for Nextcloud is a comprehensive 3D model viewer application for Nextcloud that supports multiple 3D file formats. In versions 1.7.9 through 3.3.1, the app's public file endpoint performed no share authorization. Anyone who knows a share token could read the shared file's contents even when the link share was protected by a password. `PublicFileController` extended `OCP\AppFramework\Controller` and marked its routes `#[PublicPage]`. Nextcloud only enforces share passwords through `PublicShareMiddleware`, which returns early for any controller that is not an `OCP\AppFramework\PublicShareController` instance — so no password, expiry, or share-type check ran for these routes. `ShareFileService::loadLinkShare()` compounded this by treating any token that `getShareByToken()` matched as authorised. A share token is the part of the URL that people paste into chats, emails, and tickets. Password protection exists precisely for the case where holding the token should not by itself grant access, and that guarantee did not hold. Requests to `GET /ocs/v2.php/apps/threedviewer/public/file/{token}/{fileId}` returned `200` with the full file body for password-protected shares, with no password and no session. Nextcloud's own share page correctly redirected such requests to the password prompt. Scope is limited to files in the formats this app handles (STL, GLB/glTF, OBJ, STEP, IFC, and the other supported 3D types). Non-3D files in the same share are unaffected. Expired shares returned `500` rather than leaking contents. This issue is fixed in 3.3.2. `PublicFileController` now extends `PublicShareController` and implements `isValidToken()`, `isPasswordProtected()`, and `getPasswordHash()`, delegating password and token validation to the framework and gaining brute-force throttling. `ShareFileService::findValidLinkShare()` additionally rejects share types other than link and email, rejects expired shares, and treats a `ShareNotFound` from the share manager as "no share" instead of letting it surface as a 500. As a workaround, disable the 3D Viewer app (`occ app:disable threedviewer`), or avoid relying on passwords to protect link shares that contain 3D model files, until you can upgrade.

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_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_