{"id":"CVE-2026-6673","summary":"Mattermost Jira plugin had unauthenticated {{/ac/installed}} lifecycle callback during pending Jira Cloud install","details":"Mattermost versions 11.7.x \u003c= 11.7.0, 11.6.x \u003c= 11.6.2, 11.5.x \u003c= 11.5.5, 10.11.x \u003c= 10.11.17 fail to authenticate Atlassian Connect installed callbacks, allowing a remote unauthenticated attacker to inject a rogue sharedSecret and disrupt the Jira integration via POST to /ac/installed during the pending-install window.. Mattermost Advisory ID: MMSA-2026-00654","aliases":["GHSA-jqgv-39mg-7c2r","GO-2026-6483"],"modified":"2026-11-07T02:48:18.934250429Z","published":"2026-06-22T13:38:56.594Z","database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/6xxx/CVE-2026-6673.json","unresolved_ranges":[{"extracted_events":[{"range":[{"introduced":"11.7.0"},{"last_affected":"11.7.0"}],"source":"AFFECTED_FIELD","strategy":"StandaloneSingleVersion"}]},{"extracted_events":[{"range":[{"introduced":"11.6.0"},{"last_affected":"11.6.2"},{"introduced":"11.5.0"},{"last_affected":"11.5.5"},{"introduced":"10.11.0"},{"last_affected":"10.11.17"}],"source":"AFFECTED_FIELD","strategy":"StandardRange"}]}],"cna_assigner":"Mattermost","cwe_ids":["CWE-306"]},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/6xxx/CVE-2026-6673.json"},{"type":"ADVISORY","url":"https://mattermost.com/security-updates"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-6673"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/mattermost/mattermost","events":[{"introduced":"5b955468ea1ea8b56c0fb10feb258a36a767d7bb"},{"fixed":"79ba3d3d83ef1562d08ffd2d29d3d9cc2636a41c"},{"introduced":"415ee16c51be59a77229cd3e0e939d27ab6468cf"},{"fixed":"16c42cd8677fcc91383da3b0cc85b8c9c0c231c3"},{"introduced":"d4f4e78835e86e2e76f76bfe797623076f5c9835"},{"fixed":"429426801b599699c8bef584447e5f4c6f09f035"},{"introduced":"a9e574a82633915f22071f0d7ca2b006f249ec2a"},{"fixed":"de117ab1cc09f4114aa7cb716fe760946ae7696c"}],"database_specific":{"extracted_events":[{"range":[{"introduced":"10.11.0"},{"fixed":"10.11.18"}],"source":"CPE_RANGE","cpe":"cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*"},{"source":"CPE_RANGE","cpe":"cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*","range":[{"introduced":"11.5.0"},{"fixed":"11.5.6"}]},{"source":"CPE_RANGE","cpe":"cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*","range":[{"introduced":"11.6.0"},{"fixed":"11.6.3"}]},{"range":[{"introduced":"11.7.0"},{"fixed":"11.7.1"}],"source":"CPE_RANGE","cpe":"cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*"}]}}],"versions":["v11.6.2","v10.11.17","v10.11.16","v11.7.0","mattermost-redux@11.7.0","@mattermost/types@11.7.0","@mattermost/shared@11.7.0","@mattermost/client@11.7.0","v10.11.15-rc1","v10.11.15","v11.6.1-rc1","v11.6.1","v10.11.14","v11.6.0","v10.11.14-rc1","v10.11.13","v10.11.13-rc1","v10.11.12","v10.11.11-rc2","v10.11.11","v10.11.11-rc1","v10.11.10","v10.11.9","v10.11.9-rc1","v10.11.8","v10.11.7","v10.11.6","v10.11.5","v10.11.4-rc3","v10.11.4","v10.11.4-rc2","v10.11.4-rc1","v10.11.3","v10.11.2-rc2","v10.11.2","v10.11.2-rc1","v10.11.1","v10.11.1-rc1","v10.11.0-rc3","v10.11.0","mattermost-redux@10.11.0","@mattermost/types@10.11.0","@mattermost/client@10.11.0"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-6673.json"}}],"schema_version":"1.9.2","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:N/I:H/A:H"}]}