How severe is CVE-2025-25279?

CVE-2025-25279 has a CVSS 3.x base score of 9.9, rated critical severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2025-25279 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 24% (98th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2025-25279?

CVE-2025-25279 affects Mattermost Mattermost Server. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2025-25279?

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

Does CVE-2025-25279 have an EU (EUVD) identifier?

Yes. CVE-2025-25279 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-4308.

When was CVE-2025-25279 published?

CVE-2025-25279 was published on 2025-02-24 and last updated on 2026-06-17.

CVE-2025-25279

CVE-2025-25279 is a critical-severity vulnerability in Mattermost Mattermost Server with a CVSS 3.x base score of 9.9. Its EPSS exploit-prediction score of 24% places it in the 98th percentile, indicating an elevated likelihood of exploitation. The underlying weakness is classified as CWE-22.

Key facts

Severity: Critical (CVSS 3.x base score 9.9)
EPSS exploit prediction: 24% (98th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2025-4308
Weakness: CWE-22
Affected product: Mattermost Mattermost Server
Published: 2025-02-24
Last modified: 2026-06-17

Description

Mattermost versions 10.4.x <= 10.4.1, 9.11.x <= 9.11.7, 10.3.x <= 10.3.2, 10.2.x <= 10.2.2 fail to properly validate board blocks when importing boards which allows an attacker could read any arbitrary file on the system via importing and exporting a specially crafted import archive in Boards.

Frequently asked questions

What is CVE-2025-25279?: Mattermost versions 10.4.x <= 10.4.1, 9.11.x <= 9.11.7, 10.3.x <= 10.3.2, 10.2.x <= 10.2.2 fail to properly validate board blocks when importing boards which allows an attacker could read any arbitrary file on the system via importing and exporting a specially crafted import archive in Boards.
How severe is CVE-2025-25279?: CVE-2025-25279 has a CVSS 3.x base score of 9.9, rated critical severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2025-25279 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 24% (98th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2025-25279?: CVE-2025-25279 affects Mattermost Mattermost Server. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2025-25279?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
Does CVE-2025-25279 have an EU (EUVD) identifier?: Yes. CVE-2025-25279 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-4308.
When was CVE-2025-25279 published?: CVE-2025-25279 was published on 2025-02-24 and last updated on 2026-06-17.

References

https://mattermost.com/security-updates

Affected products (1)

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

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