What is CVE-2025-53857?

CVE-2025-53857 is a low-severity vulnerability in Mattermost Confluence, classified under Missing Authorization. CVSS score: 3.7/10. Published 2025-08-11.

How severe is CVE-2025-53857?

Low severity. CVSS v3 base score is 3.7 out of 10.

Is CVE-2025-53857 known to be exploited?

1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

Auth bypass in Mattermost Confluence

CVE-2025-53857

Mattermost Confluence Plugin version <1.5.0 fails to check the access of the user to the channel which allows attackers to get channel subscription details without proper access to the channel via API call to the GET autocomplete/GetChanne…

Vulnerability class: Broken Access Control

EPSS: 0.002 (9.1th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 3.7 (Low). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N.

Affected products

Mattermost Confluence
Mattermost Confluence Plugin — versions 0, 1.5.0

Weakness classification (CWE)

CWE-862 — Missing Authorization

Public proof-of-concept exploits

fkie-cad/nvd-json-data-feeds

References

responsibledisclosure@mattermost.com (Vendor Advisory)

Frequently asked questions

What is CVE-2025-53857?: CVE-2025-53857 is a low-severity vulnerability in Mattermost Confluence, classified under Missing Authorization. CVSS score: 3.7/10. Published 2025-08-11.
How severe is CVE-2025-53857?: Low severity. CVSS v3 base score is 3.7 out of 10.
Is CVE-2025-53857 known to be exploited?: 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.