# CVE-2026-19600: Mattermost logs plaintext authentication tokens in debug-level server logs on failed auth attempts

> CVE-2026-19600: Mattermost logs plaintext authentication tokens in debug-level server logs on failed auth attempts. CVSS 4.5 (CVSS 3.1).

Canonical: https://rewindex.com/cve/CVE-2026-19600
Last updated: 2026-10-16T19:23:18Z

- Published: 2026-10-16 07:07 UTC · Updated: 2026-10-16 19:23 UTC · Assigner: Mattermost
- CVSS: 4.5 (CVSS 3.1) · Severity: Medium · Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:H/I:N/A:N
- EPSS: 0.24%, 15th percentile (scored 2026-10-25)
- CISA KEV: no
- CWE: CWE-532

## Description

Mattermost versions 11.9.x \<= 11.9.1, 11.8.x \<= 11.8.5, 11.7.x \<= 11.7.10, 11.10.x \<= 11.10.1 fail to sanitize authentication tokens before writing them to server log entries, which allows an attacker with access to server logs to obtain valid session tokens or OAuth access tokens and impersonate authenticated users via the debug-level Mattermost server log.. Mattermost Advisory ID: MMSA-2026-00763

## 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-2026-19600)
- [NVD entry](https://nvd.nist.gov/vuln/detail/CVE-2026-19600)
- [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-2026-19600 · Markdown: https://rewindex.com/cve/CVE-2026-19600.md · JSON: https://rewindex.com/api/v1/cves/CVE-2026-19600 · Data licensed CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/) · Generated 2026-10-26T02:47:11.012Z