GHSA-8r89-8w26-cq32
Suggest an improvement- Source
- https://github.com/advisories/GHSA-8r89-8w26-cq32
- Import Source
- https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/05/GHSA-8r89-8w26-cq32/GHSA-8r89-8w26-cq32.json
- JSON Data
- https://api.osv.dev/v1/vulns/GHSA-8r89-8w26-cq32
- Aliases
- Published
- 2026-05-18T09:31:48Z
- Modified
- 2026-06-25T19:56:31Z
- Severity
-
- 6.5 (Medium) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N CVSS Calculator
- Summary
- Mattermost doesn't verify channel membership when processing AI-assisted message rewrites
- Details
-
Mattermost versions 11.5.x <= 11.5.1 fail to verify channel membership when processing AI-assisted message rewrites which allows an authenticated attacker to read the content of threads in private channels and direct messages they do not have access to via a crafted request to the post rewrite endpoint.. Mattermost Advisory ID: MMSA-2026-00645
- Database specific
{ "cwe_ids": [ "CWE-862" ], "github_reviewed": true, "github_reviewed_at": "2026-06-01T15:27:00Z", "nvd_published_at": "2026-05-18T09:16:23Z", "severity": "MODERATE" }- References
Affected packages
Go
github.com/mattermost/mattermost/server/v8
Package
- Name
- github.com/mattermost/mattermost/server/v8
- View open source insights on deps.dev
- Purl
- pkg:golang/github.com/mattermost/mattermost/server/v8
github.com/mattermost/mattermost/server/v8
Package
- Name
- github.com/mattermost/mattermost/server/v8
- View open source insights on deps.dev
- Purl
- pkg:golang/github.com/mattermost/mattermost/server/v8
github.com/mattermost/mattermost-server
Package
- Name
- github.com/mattermost/mattermost-server
- View open source insights on deps.dev
- Purl
- pkg:golang/github.com/mattermost/mattermost-server