Mattermost Microsoft Teams Plugin fails to properly mask sensitive configuration values

Description

Mattermost Plugins versions <=2.0.3.0 fail to properly mask sensitive configuration values which allows an attacker with access to support packets to obtain original plugin settings via exported configuration data. Mattermost Advisory ID: MMSA-2026-00606

Basic information

Type
reviewed
Severity
high
Advisory on GitHub
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Repository advisory
Source code
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Published (advisory)
2026-03-16 15:30:43 UTC
Updated
2026-03-19 19:25:26 UTC
GitHub reviewed
2026-03-19 19:25:25 UTC
NVD published
2026-03-16 14:19:30 UTC

EPSS Score

Score Percentile
0.04% 10.66%

CVSS Scores

Base score Version Severity Vector
7.6 3.1
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:L/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:H)
They need powerful rights—admin, root, or similar—before this pays off.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N)
Service keeps running; no real outage angle.

Identifiers

CWEs

CWE id Name
CWE-200 Exposure of Sensitive Information to an Unauthorized Actor

Affected packages (1)

Vulnerable version ranges and first patched releases as published by GitHub.

Ecosystem Package Vulnerable range First patched Vulnerable functions
go github.com/mattermost/mattermost-plugin-msteams < 1.15.1-0.20260102165339-036c761bd3cb 1.15.1-0.20260102165339-036c761bd3cb

References

cvelogic Threat Intelligence