6.5
MEDIUM CVSS 3.1
CVE-2026-91181
Data Retention Teams Endpoint Leaks Private Team Invite ID
Description

Mattermost versions 11.9.x <= 11.9.0, 11.8.x <= 11.8.4, 11.7.x <= 11.7.7, 10.11.x <= 10.11.22 Fail to sanitize Team objects returned by the data retention teams endpoint which allows an authenticated user holding only the read-only Data Retention Policy permission to obtain a private team's secret invite_id and email, and use it to join the team without authorization, via GET /api/v4/data_retention/policies/{policy_id}/teams.. Mattermost Advisory ID: MMSA-2026-00702

INFO

Published Date :

Sept. 14, 2026, 9:21 p.m.

Last Modified :

Sept. 14, 2026, 9:21 p.m.

Remotely Exploit :

Yes !

Source :

Mattermost
Affected Products

The following products are affected by CVE-2026-91181 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

No affected product recoded yet

CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 3.1 MEDIUM 9302f53e-dde5-4bf3-b2f2-a83f91ac0eee
Solution
Update Mattermost to a version that addresses the data retention endpoint authorization bypass vulnerability.
  • Update Mattermost to a patched version.
  • Restrict read-only Data Retention Policy permissions.
  • Review access to the data retention teams endpoint.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-91181 vulnerability anywhere in the article.

EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.