# CVE-2026-6347: Mattermost Calls plugin exposes TURN server credentials in plaintext in support packets

> CVE-2026-6347: Mattermost Calls plugin exposes TURN server credentials in plaintext in support packets. CVSS 7.6 (CVSS 3.1).

Canonical: https://rewindex.com/cve/CVE-2026-6347
Last updated: 2026-10-14T20:10:00Z

- Published: 2026-05-18 08:30 UTC · Updated: 2026-10-14 20:10 UTC · Assigner: Mattermost
- CVSS: 7.6 (CVSS 3.1) · Severity: High · Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:N/A:L
- EPSS: 0.27%, 18th percentile (scored 2026-10-25)
- CISA KEV: no
- CWE: CWE-200

## Description

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

## Affected vendors and products

- Mattermost: Mattermost

## Tracked companies

- [Mattermost](https://rewindex.com/company/mattermost.md)

## References

- [CVE record on cve.org](https://www.cve.org/CVERecord?id=CVE-2026-6347)
- [NVD entry](https://nvd.nist.gov/vuln/detail/CVE-2026-6347)
- [https://mattermost.com/security-updates](https://mattermost.com/security-updates)

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_Sources: CVE records from the CVE Program (cve.org). CVE® is a registered trademark of The MITRE Corporation. (https://www.cve.org/) This product uses data from the NVD API but is not endorsed or certified by the NVD. (https://nvd.nist.gov/) Known Exploited Vulnerabilities catalog from CISA. (https://www.cisa.gov/known-exploited-vulnerabilities-catalog) EPSS scores from FIRST (Exploit Prediction Scoring System). (https://www.first.org/epss/)_


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Canonical: https://rewindex.com/cve/CVE-2026-6347 · Markdown: https://rewindex.com/cve/CVE-2026-6347.md · JSON: https://rewindex.com/api/v1/cves/CVE-2026-6347 · Data licensed CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/) · Generated 2026-10-26T04:04:03.533Z