CVE-2026-4265

MEDIUM EPSS 12.2%
Published Mar 16, 20263mo ago · Modified Jun 17, 20261w ago
4.3 CVSS 3.1
Medium
Find Similar
Published Mar 16, 2026 3mo ago
Last Modified Jun 17, 2026 1w ago

Description

Mattermost versions 11.3.x <= 11.3.0, 11.2.x <= 11.2.2, 10.11.x <= 10.11.10 fail to validate team-specific upload_file permissions which allows a guest user to post files in channels where they lack upload_file permission via uploading files in a team where they have permission and reusing the file metadata in a POST request to a different team. Mattermost Advisory ID: MMSA-2025-00553

CVSS Details

Base Score
4.3
Exploitability
2.8
Impact
1.4
Vector string
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N
Attack Vector Network
Attack Complexity Low
Privileges Required Low
User Interaction None
Scope Unchanged
Confidentiality None
Integrity Low
Availability None

Threat Intelligence

EPSS Exploit Probability
12.2% percentile
Exploit & Patch Status
No Known Exploit
No Patch Available

Weaknesses 1

CWE-863 Incorrect Authorization Authorization

Affected Products 3

VendorProductVersionRange
mattermostmattermost_server*≥10.11.0  –  <10.11.11
mattermostmattermost_server*≥11.2.0  –  <11.2.3
mattermostmattermost_server*≥11.3.0  –  <11.3.1

References 1

  • mattermost.com https://mattermost.com/security-updates
    Vendor Advisory

Remediation

No remediation data recorded yet

Check vendor advisories and the NVD entry for patch availability.