Path Traversal in Mattermost

CVE-2026-3112

Mattermost versions 11.4.x <= 11.4.0, 11.3.x <= 11.3.1, 11.2.x <= 11.2.3, 10.11.x <= 10.11.11 fail to validate Advanced Logging file target paths which allows system administrators to read arbitrary host files via malicious AdvancedLoggingJSON configuration in support packet generation. Mattermost Advisory ID: MMSA-2025-00562

Vulnerability class: Path Traversal (Directory Traversal)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 6.8 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:N/A:N.

EPSS exploit prediction

EPSS: 0.005 (38.6th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 39th percentile — 38.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-3112: held from 0.004 to 0.005.

EPSS over last 30 days · oldest: 0.004 · newest: 0.005 · change: +0.001

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-3112?
CVE-2026-3112 is a medium-severity vulnerability in Mattermost, classified under Path Traversal. CVSS score: 6.8/10. Published 2026-03-26.
How severe is CVE-2026-3112?
Medium severity. CVSS v3 base score is 6.8 out of 10.