# CVE-2026-104189: 3Dviewer-Nextcloud: Share password not enforced when streaming 3D models from a public link share


- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Fix available:** No
- **Published:** 27 Oct 2026
- **Updated:** 27 Oct 2026
- **Also known as:** GHSA-gjh8-x4wm-3cfj

## What is CVE-2026-104189?

CVE-2026-104189 is a high-severity vulnerability in maz1987in 3Dviewer-Nextcloud, published on 27 Oct 2026. 

### Official description

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.

Weakness: CWE-863 (Incorrect Authorization), CWE-306 (Missing Authentication for Critical Functionality)

## Which versions are affected by CVE-2026-104189?


## How do I fix CVE-2026-104189?

No fix has been published for CVE-2026-104189 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-104189 being exploited?

There is no known exploitation of CVE-2026-104189 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-104189 and fix it if it is affected.

What it is: CVE-2026-104189 is a high-severity vulnerability in maz1987in 3Dviewer-Nextcloud, published on 27 Oct 2026. 
Exploitation: There is no known exploitation of CVE-2026-104189 in the wild and no public exploit code.

Affected product: maz1987in 3Dviewer-Nextcloud. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-104189/ (Markdown: https://insights.sbomify.com/CVE-2026-104189/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-104189
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-104189
- OSV: https://osv.dev/vulnerability/CVE-2026-104189

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-104189/
Summaries are generated and may contain mistakes; the official description above is the record.