Mattermost Desktop App <=6.1 URL Overflow Crash via window.open
CVE-2026-8683 Published on June 15, 2026

Overly long URLs crash the Mattermost Desktop App
Mattermost Desktop App versions <=6.1 5.5.13.0 fail to account for attempting to open extremely long URLs in the Mattermost Desktop App which allows a malicious server owner to crash the application via including a script to call window.open on a very large URL. Mattermost Advisory ID: MMSA-2026-00652

Vendor Advisory NVD

Vulnerability Analysis

CVE-2026-8683 can be exploited with network access, requires user interaction. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have no impact on confidentiality and integrity, and a high impact on availability.

Attack Vector:
NETWORK
Attack Complexity:
LOW
Privileges Required:
NONE
User Interaction:
REQUIRED
Scope:
UNCHANGED
Confidentiality Impact:
NONE
Integrity Impact:
NONE
Availability Impact:
HIGH

Weakness Type

Allocation of Resources Without Limits or Throttling

The software allocates a reusable resource or group of resources on behalf of an actor without imposing any restrictions on the size or number of resources that can be allocated, in violation of the intended security policy for that actor.


Products Associated with CVE-2026-8683

Want to know whenever a new CVE is published for MatterMost? stack.watch will email you.

MatterMost
 

Affected Versions

Mattermost:

Exploit Probability

EPSS
0.20%
Percentile
9.76%

EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.