How severe is CVE-2025-3227?

CVE-2025-3227 has a CVSS 3.x base score of 4.3, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is low, integrity none, and availability none.

Is CVE-2025-3227 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (11th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2025-3227?

CVE-2025-3227 primarily affects Mattermost Mattermost Server. In total, 5 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2025-3227?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2025-3227 have an EU (EUVD) identifier?

Yes. CVE-2025-3227 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-18758.

When was CVE-2025-3227 published?

CVE-2025-3227 was published on 2025-06-20 and last updated on 2026-06-17.

CVE-2025-3227

CVE-2025-3227 is a medium-severity vulnerability in Mattermost Mattermost Server with a CVSS 3.x base score of 4.3. 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-863.

Key facts

Severity: Medium (CVSS 3.x base score 4.3)
EPSS exploit prediction: 0% (11th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2025-18758
Weakness: CWE-863
Affected product: Mattermost Mattermost Server
Published: 2025-06-20
Last modified: 2026-06-17

Description

Mattermost versions 10.5.x <= 10.5.5, 9.11.x <= 9.11.15, 10.8.x <= 10.8.0, 10.7.x <= 10.7.2, 10.6.x <= 10.6.5 fail to properly enforce channel member management permissions in playbook runs, allowing authenticated users without the 'Manage Channel Members' permission to add or remove users from public and private channels by manipulating playbook run participants when the run is linked to a channel.

Frequently asked questions

What is CVE-2025-3227?: Mattermost versions 10.5.x <= 10.5.5, 9.11.x <= 9.11.15, 10.8.x <= 10.8.0, 10.7.x <= 10.7.2, 10.6.x <= 10.6.5 fail to properly enforce channel member management permissions in playbook runs, allowing authenticated users without the 'Manage Channel Members' permission to add or remove users from public and private channels by manipulating playbook run participants when the run is linked to a channel.
How severe is CVE-2025-3227?: CVE-2025-3227 has a CVSS 3.x base score of 4.3, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is low, integrity none, and availability none.
Is CVE-2025-3227 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (11th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2025-3227?: CVE-2025-3227 primarily affects Mattermost Mattermost Server. In total, 5 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2025-3227?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2025-3227 have an EU (EUVD) identifier?: Yes. CVE-2025-3227 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-18758.
When was CVE-2025-3227 published?: CVE-2025-3227 was published on 2025-06-20 and last updated on 2026-06-17.

References

https://mattermost.com/security-updates

Affected products (5)

cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*
cpe:2.3:a:mattermost:mattermost_server:10.8.0:-:*:*:*:*:*:*
cpe:2.3:a:mattermost:mattermost_server:10.8.0:rc1:*:*:*:*:*:*
cpe:2.3:a:mattermost:mattermost_server:10.8.0:rc2:*:*:*:*:*:*
cpe:2.3:a:mattermost:mattermost_server:10.8.0:rc3:*:*:*:*:*:*

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