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TI-2026-81364 Aliases CVE-2026-104189

Share password bypass in 3Dviewer for Nextcloud exposes 3D files

Priority LOW 39CWE-306Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
Security bypass
Confidentiality · integrity · availability
High · None · None
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-306.

Summary

3Dviewer-Nextcloud from 1.7.9 before 3.3.2 performs no share authorization on its public file endpoint, which is a missing authentication flaw (CWE-306). An unauthenticated remote attacker who knows a share token can read 3D model files from link shares that are protected by a password. The flaw covers 3D file formats handled by the app, and other files in the same share are unaffected.

Written with Claude Haiku 5.5 from the sources below · 2026-11-02

Description from the CNA

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00353 29th percentileScored 2026-11-07
Fix Fixed 3Dviewer-Nextcloud (maz1987in): 3.3.2

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
Yes
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
maz1987in3Dviewer-Nextcloud1.7.9 to before 3.3.23.3.2Patch availableCNA
  • 3Dviewer-Nextcloud Vendormaz1987in Affected 1.7.9 to before 3.3.2 Fixed in 3.3.2 Patch available CNA

Remediation

Upgrade 3Dviewer-Nextcloud to version 3.3.2, which fixes this flaw. Until you can upgrade, disable the app with occ app:disable threedviewer, or avoid relying on share passwords to protect link shares that contain 3D model files.

Written with Claude Haiku 5.5 from the sources below · 2026-11-02

  • Fix · CNA 3Dviewer-Nextcloud (maz1987in) Fixed in 3.3.2

Timeline

  1. 2026-10-27 Threatist record created from CVE-2026-104189
  2. 2026-10-28 Priority changed: MEDIUM → LOW
  3. 2026-11-02 CISA SSVC decision points changed

References

Sources

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