CVE-2025-6465 | Path traversal in image upload with preview overwrite

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.

Published: 2025-08-21 Last update: 2025-10-02 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2025-6465 is rated Low Risk (24.2/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.06%). Mandatory action: Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2025-6465

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-01-18 0.05% 0.06% +0.02%
2 2026-01-17 0.05% 0.05% -0.00%
3 2025-08-27 0.05%

Full EPSS history (4 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2025-6465

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
4.3 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N)
Service keeps running; no real outage angle.
2.8 1.4 [email protected]

Weakness enumeration for CVE-2025-6465

GitHub Security Advisory for CVE-2025-6465

GHSA-pj6f-rc94-gw53 · Severity: medium · Ecosystem: go — Mattermost Fails to Sanitize File Names

Affected software / configurations for CVE-2025-6465

Vendor Product Version Raw CPE
mattermost mattermost_server >= 10.5.0, < 10.5.9 cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*
mattermost mattermost_server >= 10.8.0, < 10.8.4 cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*
mattermost mattermost_server >= 10.9.0, < 10.9.4 cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*
mattermost mattermost_server 10.10.0 cpe:2.3:a:mattermost:mattermost_server:10.10.0:-:*:*:*:*:*:*

References for CVE-2025-6465

URL Tags
https://mattermost.com/security-updates Vendor Advisory
cvelogic Threat Intelligence