GitHub Advisoryadvisory · Go

GHSA-8qq9-cqj8-82w4 Mattermost doesn't sanitize FileInfo.Name received from federated peers during shared channel file sync

HIGH Published 2026-06-12 Modified 2026-08-24 Official page ↗
Aliases
CVE-2026-6961
Ecosystem
Go
Packages
github.com/mattermost/mattermost-server, github.com/mattermost/mattermost/server/v8
Severity
High
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:N/I:H/A:L
Weaknesses
CWE-22
Reviewed
2026-08-24

Affected packages

• Go github.com/mattermost/mattermost-server: >= 11.6.0, < 11.6.1 → fixed in 11.6.1 • Go github.com/mattermost/mattermost-server: >= 11.5.0, < 11.5.5 → fixed in 11.5.5 • Go github.com/mattermost/mattermost-server: >= 10.11.0, < 10.11.17 → fixed in 10.11.17 • Go github.com/mattermost/mattermost/server/v8: >= 8.0.0-20250731163400-5b955468ea1e, < 8.0.0-20260423180926-c021eeaff8f0 → fixed in 8.0.0-20260423180926-c021eeaff8f0

Description

Mattermost versions 11.6.x <= 11.6.1, 11.5.x <= 11.5.4, 10.11.x <= 10.11.15, 10.11.x <= 10.11.16 fail to sanitize FileInfo.Name received from federated peers during shared channel file sync, which allows an attacker who controls a federated server to write files to arbitrary locations within the target server's filestore via path traversal sequences in the filename field. Mattermost Advisory ID: MMSA-2026-00661

Related

Alias · CVE (1)

  • CVE-2026-6961 Mattermost versions 11.6.x <= 11.6.1, 11.5.x <= 11.5.4, 10.11.x <= 10.11.15, 10.11.x <= 10.11.16 Mattermost fails to sanitize FileInfo.Name… vulnerability

Weakness · CWE (1)

  • CWE-22 Improper Limitation of a Pathname to a Restricted Directory weakness

References