# CVE-2026-10542

## Summary

- **CVE ID:** CVE-2026-10542
- **Severity:** MEDIUM
- **CVSS Score:** 5 (CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:L)
- **CWE:** CWE-639
- **Published:** Sep 14, 2026
- **Last Modified:** Sep 14, 2026

## Description

Mattermost versions 11.9.x <= 11.9.0, 11.8.x <= 11.8.4, 11.7.x <= 11.7.7, 10.11.x <= 10.11.22 fail to validate channel action ownership which allows channel managers to update actions in other channels via the channel action update endpoint.. Mattermost Advisory ID: MMSA-2026-00692

## Affected Products

- Mattermost — Mattermost (11.9.0)
- Mattermost — Mattermost (11.8.0)
- Mattermost — Mattermost (11.7.0)
- Mattermost — Mattermost (10.11.0)
- Mattermost — Mattermost (11.10.0)
- Mattermost — Mattermost (11.9.1)
- Mattermost — Mattermost (11.8.5)
- Mattermost — Mattermost (11.7.8)
- Mattermost — Mattermost (10.11.23)

## References

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

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.13%
- **EPSS Percentile:** 2.9

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-17._