CVE-2025-27936: ms teams — Fix

Description

Mattermost Plugin MSTeams versions <2.1.0 and Mattermost Server versions 10.5.x <=10.5.1 with the MS Teams plugin enabled fail to perform constant time comparison on a MSTeams plugin webhook secret which allows an attacker to retrieve the webhook secret of the MSTeams plugin via a timing attack during webhook secret comparison.

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CVSS v3.1 Score

5.3

MEDIUM

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

Weakness Type (CWE)

CWE-208 CWE-208

Affected Products

Vendor	Product	Versions
mattermost	mattermost_server	< 10.5.2
mattermost	ms_teams	< 2.1.0

References

Advisories & Patches

https://mattermost.com/security-updates

Frequently Asked Questions

What is CVE-2025-27936? +

Mattermost Plugin MSTeams versions <2.1.0 and Mattermost Server versions 10.5.x <=10.5.1 with the MS Teams plugin enabled fail to perform constant time comparison on a MSTeams plugin webhook secret which allows an attacker to retrieve the webhook secret of the MSTeams plugin via a timing attack during webhook secret comparison. It has a CVSS v3.1 base score of 5.3 (MEDIUM).

How severe is CVE-2025-27936? +

CVE-2025-27936 has a CVSS v3.1 score of 5.3 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance.

What products are affected by CVE-2025-27936? +

CVE-2025-27936 affects products from mattermost, specifically: mattermost_server, ms_teams. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2025-27936? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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