Mattermost versions 11.5.x <= 11.5.1 fail to validate team-level run_create permission against the target team when creating a playbook run which allows an authenticated team member to create runs in teams where they lack permission via specifying a different team ID in the run creation API request. Mattermost Advisory ID: MMSA-2026-00629
{
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/4xxx/CVE-2026-4055.json",
"unresolved_ranges": [
{
"source": "AFFECTED_FIELD",
"extracted_events": [
{
"introduced": "11.5.0"
},
{
"last_affected": "11.5.1"
}
]
}
],
"cna_assigner": "Mattermost",
"cwe_ids": [
"CWE-863"
]
}{
"cpe": "cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*",
"source": "CPE_RANGE",
"extracted_events": [
{
"introduced": "10.11.0"
},
{
"fixed": "10.11.17"
},
{
"introduced": "11.5.0"
},
{
"fixed": "11.5.5"
},
{
"introduced": "11.6.0"
},
{
"fixed": "11.6.2"
}
]
}