Docmost: Broken access control in transclusion lookup API leaks sync-block content across private spaces

Versions reported by the vendor

Affected version ranges reported by the assigning authority (GitHub_M). Independent of NVD's CPE analysis and usually ahead of it.

• docmost docmost

  • < 0.90.1affected

Other highest-scoring records for the same primary product.

• CVE-2026-22249Docmost affected by an Arbitrary File Write via Zip Import Feature (ZipSlip)
  39Monitor
• CVE-2026-48070Docmost: Avatar URL path traversal in avatar cleanup leads to arbitrary local file deletion
  28Monitor
• CVE-2026-65827Docmost: Unbounded ZIP decompression (zip-bomb) in page import allows denial of service
  26Monitor

Published before and after this one in the same product

• ← EarlierCVE-2026-48072Sep 24, 2026 · Docmost: Public image fileName path traversal leads to unauthorized local file read
  21Monitor
• ← EarlierCVE-2026-48073Sep 24, 2026 · Docmost: Page export can include restricted same-space attachments through forged attachmentId
  17Monitor
• Later →CVE-2026-52853Sep 24, 2026 · Docmost: Privilege Escalation - ADMIN Can Invite Users as OWNER
  20Monitor

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Root cause

The endpoint fetches the record by the ID sent in the request, but never checks whether the record belongs to the requesting user.

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

1const invoice = await Invoice.findById(req.params.id);2res.json(invoice);

1const invoice = await Invoice.findOne({2  id: req.params.id,3  ownerId: req.user.id,4});5if (!invoice) return res.sendStatus(404);6res.json(invoice);

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.