How severe is CVE-2025-6465?

CVE-2025-6465 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 none, integrity low, and availability none.

Is CVE-2025-6465 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (49th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2025-6465?

CVE-2025-6465 primarily affects Mattermost Mattermost Server. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2025-6465?

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

Does CVE-2025-6465 have an EU (EUVD) identifier?

Yes. CVE-2025-6465 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-25460.

When was CVE-2025-6465 published?

CVE-2025-6465 was published on 2025-08-21 and last updated on 2026-06-17.

CVE-2025-6465

CVE-2025-6465 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-22.

Key facts

Severity: Medium (CVSS 3.x base score 4.3)
EPSS exploit prediction: 1% (49th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2025-25460
Weakness: CWE-22
Affected product: Mattermost Mattermost Server
Published: 2025-08-21
Last modified: 2026-06-17

Description

Mattermost versions 10.8.x <= 10.8.3, 10.5.x <= 10.5.8, 10.10.x <= 10.10.0, 10.9.x <= 10.9.3 fail to sanitize file names which allows users with file upload permission to overwrite file attachment thumbnails via path traversal in file streaming APIs.

Frequently asked questions

What is CVE-2025-6465?: Mattermost versions 10.8.x <= 10.8.3, 10.5.x <= 10.5.8, 10.10.x <= 10.10.0, 10.9.x <= 10.9.3 fail to sanitize file names which allows users with file upload permission to overwrite file attachment thumbnails via path traversal in file streaming APIs.
How severe is CVE-2025-6465?: CVE-2025-6465 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 none, integrity low, and availability none.
Is CVE-2025-6465 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (49th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2025-6465?: CVE-2025-6465 primarily affects Mattermost Mattermost Server. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2025-6465?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2025-6465 have an EU (EUVD) identifier?: Yes. CVE-2025-6465 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-25460.
When was CVE-2025-6465 published?: CVE-2025-6465 was published on 2025-08-21 and last updated on 2026-06-17.

References

https://mattermost.com/security-updates

Affected products (2)

cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*
cpe:2.3:a:mattermost:mattermost_server:10.10.0:-:*:*:*:*:*:*

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