Mattermost versions 10.5.x <= 10.5.1, 10.4.x <= 10.4.3, 9.11.x <= 9.11.9 fail to check the "Allow Users to View Archived Channels" configuration when fetching channel metadata of a post from archived channels, which allows authenticated users to access such information when a channel is archived.
{
"unresolved_ranges": [
{
"source": "AFFECTED_FIELD",
"extracted_events": [
{
"introduced": "10.5.0"
},
{
"last_affected": "10.5.1"
},
{
"introduced": "10.4.0"
},
{
"last_affected": "10.4.3"
},
{
"introduced": "9.11.0"
},
{
"last_affected": "9.11.9"
}
]
}
],
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/27xxx/CVE-2025-27571.json",
"cna_assigner": "Mattermost",
"cwe_ids": [
"CWE-863"
]
}{
"source": "CPE_RANGE",
"cpe": "cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*",
"extracted_events": [
{
"introduced": "9.11.0"
},
{
"fixed": "9.11.10"
},
{
"introduced": "10.4.0"
},
{
"fixed": "10.4.4"
},
{
"introduced": "10.5.0"
},
{
"fixed": "10.5.2"
}
]
}