Vulnerability Description
Mattermost versions 11.3.x <= 11.3.0 fail to preserve the redacted state of burn-on-read posts during deletion which allows channel members to access unrevealed burn-on-read message contents via the WebSocket post deletion event.. Mattermost Advisory ID: MMSA-2026-00579
CVSS Score
MEDIUM
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Mattermost | Mattermost Server | >= 11.3.0, < 11.3.1 |
Related Weaknesses (CWE)
References
- https://mattermost.com/security-updatesVendor Advisory
FAQ
What is CVE-2026-2578?
CVE-2026-2578 is a vulnerability with a CVSS score of 4.3 (MEDIUM). Mattermost versions 11.3.x <= 11.3.0 fail to preserve the redacted state of burn-on-read posts during deletion which allows channel members to access unrevealed burn-on-read message contents via the W...
How severe is CVE-2026-2578?
CVE-2026-2578 has been rated MEDIUM with a CVSS base score of 4.3/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-2578?
Check the references section above for vendor advisories and patch information. Affected products include: Mattermost Mattermost Server.