{"id":"GHSA-mh4x-rmrx-3hp4","summary":"Mattermost has session spoofing due to lack of single-use consumption of guest magic link tokens enforcement","details":"Mattermost versions 10.11.x \u003c= 10.11.12, 11.5.x \u003c= 11.5.0, 11.4.x \u003c= 11.4.2, 11.3.x \u003c= 11.3.2 fail to enforce atomic single-use consumption of guest magic link tokens, which allows an attacker with access to a valid magic link to establish multiple independent authenticated sessions via concurrent requests. Mattermost Advisory ID: MMSA-2026-00624.","aliases":["CVE-2026-3590","GO-2026-5507"],"modified":"2026-06-25T23:11:44.105865703Z","published":"2026-04-17T15:31:17Z","database_specific":{"cwe_ids":["CWE-367"],"severity":"MODERATE","github_reviewed":true,"github_reviewed_at":"2026-04-28T22:57:43Z","nvd_published_at":"2026-04-15T12:16:40Z"},"references":[{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-3590"},{"type":"PACKAGE","url":"https://github.com/mattermost/mattermost"},{"type":"WEB","url":"https://mattermost.com/security-updates"}],"affected":[{"package":{"name":"github.com/mattermost/mattermost/server/v8","ecosystem":"Go","purl":"pkg:golang/github.com/mattermost/mattermost/server/v8"},"ranges":[{"type":"SEMVER","events":[{"introduced":"8.0.0-20250721062209-4952acea88ce"},{"fixed":"8.0.0-20250723052842-4cb8d8940332"}]}],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/04/GHSA-mh4x-rmrx-3hp4/GHSA-mh4x-rmrx-3hp4.json"}},{"package":{"name":"github.com/mattermost/mattermost-server","ecosystem":"Go","purl":"pkg:golang/github.com/mattermost/mattermost-server"},"ranges":[{"type":"SEMVER","events":[{"introduced":"10.11.0-rc1"},{"fixed":"10.11.13"}]}],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/04/GHSA-mh4x-rmrx-3hp4/GHSA-mh4x-rmrx-3hp4.json"}},{"package":{"name":"github.com/mattermost/mattermost-server","ecosystem":"Go","purl":"pkg:golang/github.com/mattermost/mattermost-server"},"ranges":[{"type":"SEMVER","events":[{"introduced":"11.5.0-rc1"},{"fixed":"11.5.0"}]}],"versions":["11.5.0-rc1"],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/04/GHSA-mh4x-rmrx-3hp4/GHSA-mh4x-rmrx-3hp4.json"}},{"package":{"name":"github.com/mattermost/mattermost-server","ecosystem":"Go","purl":"pkg:golang/github.com/mattermost/mattermost-server"},"ranges":[{"type":"SEMVER","events":[{"introduced":"11.4.0-rc1"},{"fixed":"11.4.3"}]}],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/04/GHSA-mh4x-rmrx-3hp4/GHSA-mh4x-rmrx-3hp4.json"}},{"package":{"name":"github.com/mattermost/mattermost-server","ecosystem":"Go","purl":"pkg:golang/github.com/mattermost/mattermost-server"},"ranges":[{"type":"SEMVER","events":[{"introduced":"11.3.0-rc1"},{"fixed":"11.3.3"}]}],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/04/GHSA-mh4x-rmrx-3hp4/GHSA-mh4x-rmrx-3hp4.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N"}]}