CVE-2025-6233: Arbitrary file read by system admin via path traversal

Severity: medium (CVSS 4.9 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.4% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-07-18 · updated 2026-06-17
Weakness: CWE-22

Description

Mattermost versions 10.8.x <= 10.8.1, 10.7.x <= 10.7.3, 10.5.x <= 10.5.7, 9.11.x <= 9.11.16 fail to sanitize input paths of file attachments in the bulk import JSONL file, which allows a system admin to read arbitrary system files via path traversal.

Affected products

Mattermost: from 9.11.0 before 9.11.17; from 10.5.0 before 10.5.8; from 10.7.0 before 10.7.4; from 10.8.0 before 10.8.2 — fixed in 10.5.8, 10.7.4, 10.8.2, 9.11.17

How to fix

Upgrade to a fixed version: Mattermost 10.5.8, 10.7.4, 10.8.2, 9.11.17. Check the vendor advisory for mitigations.

References

https://mattermost.com/security-updates

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