CVE-2025-10545

Name: CVE-2025-10545
Creator: NVD / NIST
Published: 2025-10-16T09:15:33.137+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 4.3/10EPSS 0.31%

Last modified Jun 17, 2026

CVE-2025-10545 is a medium-severity vulnerability rated 4.3/10 on the CVSS scale. Mattermost versions 10.5.x <= 10.5.10, 10.11.x <= 10.11.2 fail to properly validate guest user permissions when adding channel members which allows guest users to add any team members to their private channels via the `/api/v4/channels/{channel_id}/members` endpoint. EPSS estimates a 0.31% chance of exploitation in the next 30 days.

Description

Mattermost versions 10.5.x <= 10.5.10, 10.11.x <= 10.11.2 fail to properly validate guest user permissions when adding channel members which allows guest users to add any team members to their private channels via the `/api/v4/channels/{channel_id}/members` endpoint

Metrics

CVSS 3.1

4.3/10

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N

EPSS Probability

0.31%

22.2th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-863

Affected Software

Vendor	Product	Versions
Mattermost	Mattermost Server	>= 10.5.0, < 10.5.11
Mattermost	Mattermost Server	>= 10.11.0, < 10.11.3

References

https://mattermost.com/security-updatesVendor Advisory

Timeline

Published: Oct 16, 2025
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2025-10545?

How severe is CVE-2025-10545?

CVE-2025-10545 has a CVSS score of 4.3/10 (MEDIUM severity). The EPSS model estimates a 0.31% probability of exploitation in the next 30 days.

How do I fix CVE-2025-10545?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2025-10545?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST