Resource exhaustion in Mattermost

CVE-2026-8683

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.op…

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-8683?
CVE-2026-8683 is a medium-severity vulnerability in Mattermost, classified under Allocation of Resources Without Limits or Throttling. CVSS score: 6.5/10. Published 2026-06-15.
How severe is CVE-2026-8683?
Medium severity. CVSS v3 base score is 6.5 out of 10.