CVE-2026-52850 Docmost: Broken access control in transclusion lookup API leaks sync-block content across private spaces
Authenticated users can access private space content via the transclusion API due to missing authorization checks, leaking confidential data.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-52850?
CVE-2026-52850 is a medium-severity missing authorization vulnerability in docmost, published on 24 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official 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.
Which versions are affected by CVE-2026-52850?
How do I fix CVE-2026-52850?
No fix has been published for CVE-2026-52850 yet. Limit exposure of the affected software until one is available.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2026-52850 being exploited?
There is no known exploitation of CVE-2026-52850 in the wild and no public exploit code.
Sources
Also known as GHSA-5vhf-cgf2-c9cq.