# CVE-2026-22880: Mobile SSO authentication flow allows credential theft via malicious server

> CVE-2026-22880: Mobile SSO authentication flow allows credential theft via malicious server. CVSS 6.1 (CVSS 3.1).

Canonical: https://rewindex.com/cve/CVE-2026-22880
Last updated: 2026-08-06T15:42:06Z

- Published: 2026-05-21 08:22 UTC · Updated: 2026-08-06 15:42 UTC · Assigner: Mattermost
- CVSS: 6.1 (CVSS 3.1) · Severity: Medium · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:N/A:N
- EPSS: 0.12%, 2th percentile (scored 2026-10-25)
- CISA KEV: no
- CWE: CWE-352

## Description

Mattermost Mobile Apps versions \<=2.37 11.4 2.0.37 11.0.4 11.1.3 11.3.2 10.11.11.0 fail to properly validate the SSO authentication callback origin which allows an attacker controlling a malicious Mattermost server to steal user credentials for a legitimate Mattermost server via relaying the SSO code exchange flow through the mobile application. Mattermost Advisory ID: MMSA-2025-00564

## 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-2026-22880)
- [NVD entry](https://nvd.nist.gov/vuln/detail/CVE-2026-22880)
- [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-2026-22880 · Markdown: https://rewindex.com/cve/CVE-2026-22880.md · JSON: https://rewindex.com/api/v1/cves/CVE-2026-22880 · Data licensed CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/) · Generated 2026-10-26T03:11:12.788Z