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.

Is your site exposed to CVE-2025-27936?

Run a free security scan — no signup, results in seconds.

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.

Related Vulnerabilities

CVE-2025-59432

SCRAM (Salted Challenge Response Authentication Mechanism) is part of the family of Simple Authentication and Security Layer (SASL, RFC 4422) …

CVE-2026-15432

When verifying a mac with a ChunkedMacVerification object, Tink compares the resulting tag with non constant time comparison. This potentially …

CVE-2025-29780

Post-Quantum Secure Feldman's Verifiable Secret Sharing provides a Python implementation of Feldman's Verifiable Secret Sharing (VSS) scheme. In versions 0.8.0b2 …

CVE-2025-7071

Padding oracle attack vulnerability in Oberon microsystem AG’s ocrypto library in all versions since 3.1.0 and prior to 3.9.2 allows …

CVE-2025-7383

Padding oracle attack vulnerability in Oberon microsystem AG’s Oberon PSA Crypto library in all versions since 1.0.0 and prior to …

CVE-2025-53940

Quiet is an alternative to team chat apps like Slack, Discord, and Element that does not require trusting a central …

CVE-2025-27936