High severity · published Jan 16, 2025
CVE-2025-20621
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…
7.5
CVSS
0.5%
EPSS
No
On KEV
Description
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
None
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.5% · higher than 41% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
MS
Mattermost Server · Mattermost
9.11.0 before 9.11.6; 10.0.0 before 10.0.4; 10.1.0 before 10.1.4; 10.2.0 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2025-20621
CVE.org
https://www.cve.org/CVERecord?id=CVE-2025-20621
Vendor Advisory
https://mattermost.com/security-updates
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