CVE-2025-55035
Mattermost Desktop DoS when user has basic authentication server configured
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- High
- Privileges needed
- None
- User interaction
- Required
What an attacker can affect
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
Mattermost Desktop DoS when user has basic authentication server configured
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.
- Record
CVE-2025-55035- CVSS 3.1
- 6.1 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:N/I:N/A:H - Weakness
- CWE-754
- Updated
- 2026-11-02
EUVDEUVD-2025-34773
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.
- Record
EUVD-2025-34773- CVSS 3.1
- 6.1 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:N/I:N/A:H - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-3359-25fv-h37v
Mattermost Desktop App versions <=5.13.0 fail to manage modals in the Mattermost Desktop App that...
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.
- Record
GHSA-3359-25fv-h37v- CVSS 3.1
- 6.1 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:N/I:N/A:H - Weakness
- CWE-754
- Updated
- 2026-11-02
NVD
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.
- Record
CVE-2025-55035- CVSS 3.1
- 6.1 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:N/I:N/A:H - Weakness
- CWE-754
- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2025-55035 is a medium vulnerability (CVSS 6.1) in Mattermost, published October 16, 2025. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.32%, the 24th percentile. No source names a fixed version.