CVE-2026-52850
Docmost: Broken access control in transclusion lookup API leaks sync-block content across private spaces
CVE-2026-52850 is a medium vulnerability (CVSS 4.3) in Docmost, published September 24, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.19%, the 9th percentile. No source names a fixed version.
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
What an attacker can affect
- Confidentiality
- Low
- Integrity
- None
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
4.3
Docmost: Broken access control in transclusion lookup API leaks sync-block content across private spaces
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.
- Record
CVE-2026-52850- CVSS 3.1
- 4.3 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N - Weakness
- CWE-639, CWE-862
- Updated
- 2026-11-02
EUVDEUVD-2026-86387
4.3
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.
- Record
EUVD-2026-86387- CVSS 3.1
- 4.3 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N - Updated
- 2026-11-02
NVD
4.3
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.
- Record
CVE-2026-52850- CVSS 3.1
- 4.3 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N - Weakness
- CWE-639, CWE-862
- Updated
- 2026-11-02
OSV
4.3
Docmost: Broken access control in transclusion lookup API leaks sync-block content across private spaces
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.
- Record
CVE-2026-52850- CVSS 3.1
- 4.3 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N - Weakness
- CWE-639, CWE-862
- Updated
- 2026-11-02
Affected products
History
| When | Changed | Sources |
|---|---|---|
| 2026-11-02 | created | CVE List, EUVD, NVD, OSV |
References
github.com/docmost/docmost/security/advisories/GHSA-5vhf-cgf2-c9cq
github.com/docmost/docmost/commit/830b5b4d458a1302f42c8b68bff9ff559f6eb342
github.com/docmost/docmost/releases/tag/v0.90.1
github.com/CVEProject/cvelistV5/tree/main/cves/2026/52xxx/CVE-2026-52850.json
nvd.nist.gov/vuln/detail/CVE-2026-52850