Auth bypass in Mattermost

CVE-2024-39830

Mattermost versions 9.8.x <= 9.8.0, 9.7.x <= 9.7.4, 9.6.x <= 9.6.2 and 9.5.x <= 9.5.5, when shared channels are enabled, fail to use constant time comparison for remote cluster tokens which allows an attacker to retrieve the remote cluster token via a timing attack during remote cluster token comparison.

Vulnerability class: Broken Authentication

EPSS: 0.004 (30.5th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 8.1 (High). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H.

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2024-39830?
CVE-2024-39830 is a high-severity vulnerability in Mattermost, classified under Improper Authentication. CVSS score: 8.1/10. Published 2024-07-03.
How severe is CVE-2024-39830?
High severity. CVSS v3 base score is 8.1 out of 10.
Is CVE-2024-39830 known to be exploited?
1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.