# CVE-2026-9597

## Summary

- **CVE ID:** CVE-2026-9597
- **Severity:** MEDIUM
- **CVSS Score:** 5.4 (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N)
- **CWE:** CWE-305
- **Published:** Jul 13, 2026
- **Last Modified:** Jul 13, 2026

## Description

Mattermost versions 11.7.x <= 11.7.2, 11.6.x <= 11.6.4 fail to verify whether a guest account is deactivated before creating a session in the magic-link token login path, which allows a deactivated guest user to obtain a fully functional session via a magic-link token issued prior to deactivation.. Mattermost Advisory ID: MMSA-2026-00681

## Affected Products

- Mattermost — Mattermost (11.7.0)
- Mattermost — Mattermost (11.6.0)
- Mattermost — Mattermost (11.8.0)
- Mattermost — Mattermost (11.7.3)
- Mattermost — Mattermost (11.6.5)

## References

- [CNA](https://mattermost.com/security-updates)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.23%
- **EPSS Percentile:** 13.8

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-10._