Vulnerability DatabaseCVE-2025-20621
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CVE-2025-20621
Published:January 16, 2025
Updated:August 06, 2026
Mattermost versions 10.2.x <= 10.2.0, 9.11.x <= 9.11.5, 10.0.x <= 10.0.3, 10.1.x <= 10.1.3 fail to properly handle posts with attachments containing fields that cannot be cast to a String, which allows an attacker to cause the webapp to crash via creating and sending such a post to a channel.
Affected Packages
github.com/mattermost/mattermost/server/v8 (GO):
Affected version(s) >=v8.0.0-20230429093631-aac4f2337933 <v8.0.0-20241127161322-25ff7a3779a5
Fix Suggestion:
Update to version v8.0.0-20241127161322-25ff7a3779a5
Related Resources (5)
https://nvd.nist.gov/vuln/detail/CVE-2025-20621
https://github.com/advisories/GHSA-w6xh-c82w-h997
https://github.com/mattermost/mattermost
https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/20xxx/CVE-2025-20621.json
https://mattermost.com/security-updates
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CVSS v4
Base Score:
7.1
Attack Vector
NETWORK
Attack Complexity
LOW
Attack Requirements
NONE
Privileges Required
LOW
User Interaction
NONE
Vulnerable System Confidentiality
NONE
Vulnerable System Integrity
NONE
Vulnerable System Availability
HIGH
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
6.5
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Weakness Type (CWE)
Improper Validation of Specified Type of Input
CWE-1287
EPSS
Base Score:
0.45