Timing attack during remote cluster token comparison when shared channels are enabled

published 2024-07-03 2 y ago modified 2026-06-17 4 mo ago also EUVD-2024-38258

cvss: 8.1; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.4%; EPSS 0.4% chance of exploitation in 30 days, percentile 32%
public exploits: 0; none known

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.

Patch / fix

fixed in 1

Mattermost Mattermost 9.5.6, 9.6.3, 9.7.5, 9.8.1, 9.9.0

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: total
Assessed: 2 y ago (2024-07-03)

Exploit prediction

0.38% chance of exploitation in the next 30 days, higher than 32% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	3.1	8.1	CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD	3.1	5.9	CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N

Affected products

Mattermost Mattermost

Classification

Weakness

CWE-287 Improper Authentication
CWE-203 Observable Discrepancy

References

mattermost.com /security-updates
vendor-advisory

Sources

CVE List CVE-2024-39830
NVD CVE-2024-39830

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Summary