How severe is CVE-2024-39830?

CVE-2024-39830 has a CVSS 3.x base score of 8.1, rated high severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2024-39830 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (30th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2024-39830?

CVE-2024-39830 affects Mattermost. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2024-39830?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

Does CVE-2024-39830 have an EU (EUVD) identifier?

Yes. CVE-2024-39830 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2024-38258.

When was CVE-2024-39830 published?

CVE-2024-39830 was published on 2024-07-03 and last updated on 2026-06-17.

CVE-2024-39830

CVE-2024-39830 is a high-severity vulnerability in Mattermost with a CVSS 3.x base score of 8.1. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-203.

Key facts

Severity: High (CVSS 3.x base score 8.1)
EPSS exploit prediction: 0% (30th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2024-38258
Weakness: CWE-203
Affected product: Mattermost
Published: 2024-07-03
Last modified: 2026-06-17

Description

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.

Frequently asked questions

What is 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.
How severe is CVE-2024-39830?: CVE-2024-39830 has a CVSS 3.x base score of 8.1, rated high severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2024-39830 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (30th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2024-39830?: CVE-2024-39830 affects Mattermost. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2024-39830?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2024-39830 have an EU (EUVD) identifier?: Yes. CVE-2024-39830 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2024-38258.
When was CVE-2024-39830 published?: CVE-2024-39830 was published on 2024-07-03 and last updated on 2026-06-17.

References

https://mattermost.com/security-updates

Affected products (1)

cpe:2.3:a:mattermost:mattermost:*:*:*:*:*:*:*:*

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