Mattermost versions 11.5.x <= 11.5.1, 10.11.x <= 10.11.13, 11.4.x <= 11.4.3 fail to sanitize sensitive configuration fields in the Mattermost Calls plugin which allows an attacker with access to a support packet to obtain TURN server credentials via the plaintext values present in the exported plugin configuration.. Mattermost Advisory ID: MMSA-2026-00605
{
"unresolved_ranges": [
{
"source": "AFFECTED_FIELD",
"extracted_events": [
{
"introduced": "11.5.0"
},
{
"last_affected": "11.5.1"
},
{
"introduced": "10.11.0"
},
{
"last_affected": "10.11.13"
},
{
"introduced": "11.4.0"
},
{
"last_affected": "11.4.3"
}
]
}
],
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/6xxx/CVE-2026-6347.json",
"cna_assigner": "Mattermost",
"cwe_ids": [
"CWE-200"
]
}{
"source": "CPE_RANGE",
"cpe": "cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*",
"extracted_events": [
{
"introduced": "10.11.0"
},
{
"fixed": "10.11.14"
},
{
"introduced": "11.4.0"
},
{
"fixed": "11.4.4"
},
{
"introduced": "11.5.0"
},
{
"fixed": "11.5.2"
}
]
}