{"url":"http://public2.vulnerablecode.io/api/vulnerabilities/73717?format=json","vulnerability_id":"VCID-vgk7-ga2z-j3dr","summary":"Mattermost versions 11.2.x <= 11.2.2, 10.11.x <= 10.11.10, 11.4.x <= 11.4.0, 11.3.x <= 11.3.1 fail to restrict team-level access when processing membership sync from a remote cluster, which allows a malicious remote cluster to grant a user access to an entire private team instead of only the shared channel via sending crafted membership sync messages that trigger team membership assignment. Mattermost Advisory ID: MMSA-2026-00574","aliases":[{"alias":"CVE-2026-4274"}],"fixed_packages":[],"affected_packages":[],"references":[{"reference_url":"https://mattermost.com/security-updates","reference_id":"security-updates","reference_type":"","scores":[{"value":"5.4","scoring_system":"cvssv3.1","scoring_elements":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N"},{"value":"Track","scoring_system":"ssvc","scoring_elements":"SSVCv2/E:N/A:N/T:P/P:M/B:A/M:M/D:T/2026-03-26T13:58:33Z/"}],"url":"https://mattermost.com/security-updates"}],"weaknesses":[{"cwe_id":863,"name":"Incorrect Authorization","description":"The product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check. This allows attackers to bypass intended access restrictions."}],"exploits":[],"severity_range_score":"5.4 - 5.4","exploitability":null,"weighted_severity":null,"risk_score":null,"resource_url":"http://public2.vulnerablecode.io/vulnerabilities/VCID-vgk7-ga2z-j3dr"}