CVE-2026-26246 Details
Description
Mattermost versions 11.3.x <= 11.3.0, 11.2.x <= 11.2.2, 10.11.x <= 10.11.10 fail to bound memory allocation when processing PSD image files which allows an authenticated attacker to cause server memory exhaustion and denial of service via uploading a specially crafted PSD file. Mattermost Advisory ID: MMSA-2026-00572
A denial-of-service vulnerability has been identified in Mattermost versions 11.3.x through 11.3.0, 11.2.x through 11.2.2, and 10.11.x through 10.11.10. The issue arises from the application's failure to properly limit memory allocation when processing PSD image files. This flaw allows an authenticated attacker to upload a specially crafted PSD file, causing server memory exhaustion and disrupting service.
Users can upgrade to Mattermost versions 11.5.0, 11.4.0, or 11.3.1 to address this vulnerability.
Metrics
CVSS 4.0 Severity and Vector Strings:
No CVSS 4.0 data is available for this CVE.
CVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
CISA-ADP
Assessed Mar 16, 2026References to Advisories, Solutions, and Tools
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| URL | Source(s) | Tag(s) |
|---|---|---|
| https://mattermost.com/security-updates | [email protected] | Vendor Advisory |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-789 | Memory Allocation with Excessive Size Value | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| mattermost mattermost server | >= 10.11.0, < 10.11.11 >= 11.2.0, < 11.2.3 >= 11.3.0, < 11.3.1 |
CPE
Remediation
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Change History
4 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jun 17, 2026 | CVE Modified | [email protected] |
| Jun 17, 2026 | CVE Modified | CISA-ADP |
| Mar 18, 2026 | Initial Analysis | [email protected] |
| Mar 16, 2026 | New CVE Received | [email protected] |