~ / search / GHSA-8qq9-cqj8-82w4

GHSA-8qq9-cqj8-82w4

Mattermost doesn't sanitize FileInfo.Name received from federated peers during shared channel file sync

Source: GitHub Advisory Database (reviewed) High CVE-2026-6961

Packages

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

Details

As written in the advisory (Markdown source, shown as plain text).

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

References

External links from the advisory. They lead to third-party sites.