Home/CVE/Mattermost versions 11.5.x <= 11.5.1, 10.11.x <= 10.11.13, 11.4.x <= 11.4.3 fail to sanitize sensitive configuration fie
CVE

CVE-2026-6347

Mattermost versions 11.5.x <= 11.5.1, 10.11.x <= 10.11.13, 11.4.x <= 11.4.3 fail to sanitize sensitive configuration fie

Mattermost versions 11.5.x <= 11.5.1, 10.11.x <= 10.11.13, 11.4.x <= 11.4.3 fail to sanitize sensitive configuration fields in the Mattermost Calls plugin which allows an attacker with access to a support packet to obtain TURN server credentials via the plaintext values present in the exported plugin configuration.. Mattermost Advisory ID: MMSA-2026-00605.

HIGH · CVSS 7.6 EPSS 0.00053
Schedule remediation
  • CVSS base score ≥ 7.0
Sigma rules0 YARA rules0
⬡

Weakness Classification

CWE-200Exposure of Sensitive Information to an Unauthorized Actor
▤

Affected Products & Versions

3
mattermost server>= 10.11.0 and < 10.11.14
mattermost server>= 11.4.0 and < 11.4.4
mattermost server>= 11.5.0 and < 11.5.2
▤

Affected Packages

2
Language-ecosystem packages (from OSV) tied to this CVE, with the version that fixes it - the dependency-level detail NVD doesn’t carry.
Go github.com/mattermost/mattermost-plugin-calls HIGH fixed in 1.12.0-rc2
Go github.com/mattermost/mattermost-server HIGH fixed in 11.5.2
▣

Scoring & Timeline

7.6
HIGH · CVSS v3.1 · responsibledisclosure@mattermost.com
View on NVD
Attack Vector
Network Adjacent Local Physical
Attack Complexity
Low High
Privileges Required
None Low High
User Interaction
None Required
Scope
Unchanged Changed
Confidentiality
None Low High
Integrity
None Low High
Availability
None Low High
Published to NVD18 May 2026 · 09:16 AM
CVSS VectorCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:N/A:L
SSVC triage · cisa-vulnrichment
Exploitation
none
Automatable
no
Technical impact
partial
SSVC asks the questions that actually drive patch urgency: is it being exploited, can attacks be automated, and how total is the impact.
🔗

References & Sources

1
Source URLs (vendor pages, mailing lists, write-ups). Exploit/PoC links are in their own section above to avoid duplication.
https://mattermost.com/security-updatesVendor Advisory
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