Mattermost is grouping calls in the /metrics endpoint by id and reports that id in the response. Since this id is the channelID, the public /metrics endpoint is revealing channelIDs.
CVE ID: CVE-2023-6459
CVSS Base Severity: MEDIUM
CVSS Base Score: 5.3
Vendor: Mattermost
Product: Mattermost
EPSS Score: 0.06% (probability of being exploited)
EPSS Percentile: 29.94% (scored less or equal to compared to others)
EPSS Date: 2025-02-03 (when was this score calculated)