Medium severity · published Oct 16, 2025
CVE-2025-55035
Mattermost Desktop DoS when user has basic authentication server configured
6.1
CVSS
0.3%
EPSS
No
On KEV
Description
Mattermost Desktop App versions <=5.13.0 fail to manage modals in the Mattermost Desktop App that stops a user with a server that uses basic authentication from accessing their server which allows an attacker that provides a malicious server to the user to deny use of the Desktop App via having the user configure the malicious server and forcing a modal popup that cannot be closed.
CVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:N/I:N/A:H
Attack vector
Network
Complexity
High
Privileges
None
User interaction
Required
Confidentiality
None
Integrity
None
Availability
High
Scope
Changed
Exploitation
Is it being used?
Exploit prediction (EPSS)0.3% · higher than 24% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
MA
Mattermost · Mattermost
through 5.0.13 · source: vendor
MD
Mattermost Desktop · Mattermost
before 5.13.1.0 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2025-55035
CVE.org
https://www.cve.org/CVERecord?id=CVE-2025-55035
Vendor Advisory
https://mattermost.com/security-updates
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