Docmost: Broken access control in transclusion lookup API leaks sync-block content across private spaces (CVE-2026-52850) | HOL Guard CVE

Medium · CVSS 4.3CVE-2026-52850

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

Answer in brief

CVE-2026-52850 records a Medium severity (CVSS 4.3) vulnerability in Docmost: Broken access control in transclusion lookup API leaks sync-block content across private spaces. The current sources do not mark it as known exploited. The current feed maps docmost/docmost (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Sep 24, 2026Updated Sep 24, 2026Source checked Sep 25, 2026First seen by HOL Sep 25, 2026Material review Sep 24, 2026

Upstream Advisory

Key facts

Risk: Medium · CVSS 4.3
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Available

Why this deserves its current priority

CVSS is 4.3. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps docmost/docmost (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
docmost/docmostgeneric	<0.90.1	0.90.1

Recommended response

Check inventory. Check lockfiles and deployed manifests for docmost/docmost.
Review the reported fix. Update docmost/docmost to 0.90.1 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Sep 24, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 24, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Sep 25, 2026

Sources and claim methodology

Upstream source description

Docmost is open-source collaborative wiki and documentation software. Prior to 0.90.1, an authenticated workspace member who does not belong to a private space can call the transclusion / sync-block lookup API with a known sourcePageId and transclusionId pair because the lookup does not enforce private space membership before resolving the source page. The API can return confidential sync-block content and source page metadata even though the normal page APIs deny access to the same page. This issue is fixed in version 0.90.1.

Quoted source text, attributed separately from HOL analysis.