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{}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[11.2.0,11.2.2]"}}, {"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[10.11.0,10.11.10]"}}, {"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[11.4.0,11.4.0]"}}, {"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[11.3.0,11.3.1]"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "11.5.0"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "11.2.3"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "10.11.11"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "11.4.1"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "11.3.2"}}], "enrichment": {"confidence": 100.0, "confidence_source": "matching", "scores": [{"score": 100.0, "source": "matching"}]}, "original": {"product": "Mattermost", "source": "cna", "vendor": "Mattermost"}, "product": "mattermost", "vendor": "mattermost"}], "analysis": {"en": {"generated_at": "2026-03-26T17:23:37.910098+00:00", "value": {"mitigation_remediation": ["Update Mattermost to a supported version (11.5.0, 11.2.3, 10.11.11, 11.4.1, 11.3.2 or higher).", "Verify that group member retrieval no longer exposes IDs beyond the allowed scope.", "If an update cannot be performed immediately, limit guest user permissions or monitor the group retrieval endpoint for suspicious activity."], "summary": {"action": "Apply Patch", "impact": "User Enumeration"}, "threat_synthesis": {"affected_systems": "The issue affects Mattermost versions 10.11.x through 10.11.10, 11.2.x through 11.2.2, 11.3.x through 11.3.1, and 11.4.x through 11.4.0. The vulnerability is present in the group retrieval endpoint and allows authenticated guest users to gather user IDs outside their permitted visibility range.", "description_and_impact": "Authenticated guest users can retrieve group member IDs without respecting view restrictions, allowing enumeration of user identities that should otherwise remain hidden. This grants insight into the internal user base and can facilitate targeted social engineering or further privilege escalation.", "risk_and_exploitability": "The CVSS score of 4.3 denotes moderate severity. No exploit probability metric is available, and the vulnerability is not listed in the CISA KEV catalog, indicating a relatively low likelihood of widespread exploitation. Nonetheless, attackers who possess legitimate guest access could leverage the enumeration capability to inform subsequent attacks. Applying the vendor patch is the most efficient mitigation."}}}}, "created": "2026-03-27T08:33:55.851188+00:00", "updated": "2026-03-27T09:26:22.202156+00:00", "vendors": ["mattermost", "mattermost$PRODUCT$mattermost"]}