Medium
Mattermost Shared Channel Upload Type Validation Bypass
Type: advisorySources: OSV
Mattermost versions 10.8.x <= 10.8.3, 10.5.x <= 10.5.8, 9.11.x <= 9.11.17, 10.9.x <= 10.9.2, 10.10.x <= 10.10.0 fail to validate upload types in remote cluster upload sessions which allows a system admin to upload non-attachment file types via shared channels that could potentially be placed in arbitrary filesystem directories.
- Products
- Not specified
- Affected versions
- Not specified
- Fixed versions
- Not specified
- CVEs
- CVE-2025-49222
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 5 Nov 2026, 17:11 UTC · Revision 1
Source evidence
Mattermost Shared Channel Upload Type Validation Bypass
core-osv · Original sourcePublished 21 Aug 2025, 07:59 UTC
Mattermost versions 10.8.x <= 10.8.3, 10.5.x <= 10.5.8, 9.11.x <= 9.11.17, 10.9.x <= 10.9.2, 10.10.x <= 10.10.0 fail to validate upload types in remote cluster upload sessions which allows a system admin to upload non-attachment file types via shared channels that could potentially be placed in arbitrary filesystem directories.
osv:CVE-2025-49222
Complete source record
{
"id": "9aacae7d5ef3d8fce78d955aa619c424340581d25dc2b3e1844af2c5e1ba495a",
"url": "https://osv.dev/vulnerability/CVE-2025-49222",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "Mattermost Shared Channel Upload Type Validation Bypass",
"summary": "Mattermost versions 10.8.x <= 10.8.3, 10.5.x <= 10.5.8, 9.11.x <= 9.11.17, 10.9.x <= 10.9.2, 10.10.x <= 10.10.0 fail to validate upload types in remote cluster upload sessions which allows a system admin to upload non-attachment file types via shared channels that could potentially be placed in arbitrary filesystem directories.",
"evidence": "osv:CVE-2025-49222",
"products": [],
"severity": "medium",
"structured": {
"id": "CVE-2025-49222",
"aliases": [
"CVE-2025-49222",
"GHSA-q453-638c-h4mr",
"GO-2025-3904"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:N/A:N"
}
],
"affected": [
{
"ranges": [
{
"repo": "https://github.com/mattermost/mattermost",
"type": "GIT",
"events": [
{
"introduced": "0bc2ddd42375a75ab14e63f038165150d4f07659"
},
{
"fixed": "11c36f4d1e44c36a85aa682becaa7519f63761cf"
},
{
"introduced": "58bd34fd34cbd7d3da777d627b6cffdf8a532930"
},
{
"fixed": "c602a4a78e1f60b9a97ee5bce509ecad4177340c"
},
{
"introduced": "bb105f3a2785636ad53b2d0bf4027900d41f6a67"
},
{
"fixed": "6880f9b5908f20c6c4db1456d3a27603af01dd72"
},
{
"introduced": "14775836a78c8257de08fff229d364755346eff9"
},
{
"fixed": "b38e2eccda182212a8032539658723c7d87e0b7e"
},
{
"introduced": "c8bd5c937551a4e9ad23f5a4fd8aaf7604d046dd"
},
{
"last_affected": "c8bd5c937551a4e9ad23f5a4fd8aaf7604d046dd"
}
],
"database_specific": {
"extracted_events": [
{
"cpe": "cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*",
"range": [
{
"introduced": "9.11.0"
},
{
"fixed": "9.11.18"
}
],
"source": "CPE_RANGE"
},
{
"cpe": "cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*",
"range": [
{
"introduced": "10.5.0"
},
{
"fixed": "10.5.9"
}
],
"source": "CPE_RANGE"
},
{
"cpe": "cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*",
"range": [
{
"introduced": "10.8.0"
},
{
"fixed": "10.8.4"
}
],
"source": "CPE_RANGE"
},
{
"cpe": "cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*",
"range": [
{
"introduced": "10.9.0"
},
{
"fixed": "10.9.3"
}
],
"source": "CPE_RANGE"
},
{
"cpe": "cpe:2.3:a:mattermost:mattermost_server:10.10.0:-:*:*:*:*:*:*",
"range": [
{
"introduced": "10.10.0-NA"
},
{
"last_affected": "10.10.0-NA"
}
],
"source": "CPE_STRING"
}
]
}
}
],
"versions": [
"10.10.0-NA",
"v10.8.4-rc4",
"v10.5.9-rc4",
"v9.11.18-rc4",
"v9.11.18-rc3",
"v10.5.9-rc3",
"v10.8.4-rc3",
"v10.5.9-rc2",
"v10.8.4-rc2",
"v10.9.3-rc3",
"v9.11.18-rc2",
"v10.10.0",
"v10.9.3-rc2",
"v9.11.18-rc1",
"v10.8.4-rc1",
"v10.9.3-rc1",
"v10.5.9-rc1",
"v10.9.2-rc1",
"v10.9.2",
"v9.11.17",
"v10.5.8",
"v10.8.3",
"v10.9.1",
"v10.8.2",
"v10.5.8-rc1",
"v9.11.17-rc1",
"v10.9.0-rc4",
"v10.9.0",
"mattermost-redux@10.8.0",
"@mattermost/types@10.8.0",
"@mattermost/client@10.8.0",
"v10.5.7",
"v9.11.16-rc1",
"v9.11.16",
"v10.5.6-rc1",
"v10.5.6",
"v10.8.1",
"v9.11.15",
"v10.5.5",
"v10.5.5-rc1",
"v9.11.14",
"v10.8.0-rc3",
"v10.8.0",
"v10.5.4-rc2",
"v10.5.4",
"v9.11.13",
"v10.5.4-rc1",
"v9.11.13-rc1",
"v10.5.3",
"v9.11.12",
"v10.5.3-rc1",
"v9.11.12-rc1",
"v9.11.11-rc1",
"v9.11.11",
"v9.11.10",
"v10.5.2",
"v9.11.10-rc1",
"v9.11.9",
"v10.5.1",
"v10.5.1-rc2",
"v10.5.1-rc1",
"v9.11.9-rc2",
"v9.11.9-rc1",
"v10.5.0-rc6",
"v10.5.0",
"@mattermost/types@10.5.0",
"@mattermost/client@10.5.0",
"v9.11.8",
"v9.11.7-rc3",
"v9.11.7",
"v9.11.7-rc2",
"v9.11.7-rc1",
"v9.11.6",
"v9.11.6-rc2",
"v9.11.6-rc1",
"v9.11.5",
"v9.11.5-rc1",
"v9.11.4",
"v9.11.4-rc1",
"v9.11.3",
"v9.11.3-rc2",
"v9.11.3-rc1",
"v9.11.2",
"v9.11.2-rc2",
"v9.11.2-rc1",
"v9.11.1-rc1",
"v9.11.1",
"v9.11.0-rc3",
"v9.11.0",
"@mattermost/types@9.11.0",
"@mattermost/client@9.11.0"
],
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2025-49222.json"
}
}
],
"modified": "2026-10-28T02:30:44.517595001Z",
"provider": "osv",
"references": [
"https://mattermost.com/security-updates",
"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/49xxx/CVE-2025-49222.json",
"https://nvd.nist.gov/vuln/detail/CVE-2025-49222"
],
"provider_metadata": {
"cwe_ids": [
"CWE-434"
],
"cna_assigner": "Mattermost",
"unresolved_ranges": [
{
"extracted_events": [
{
"range": [
{
"introduced": "10.10.0"
},
{
"last_affected": "10.10.0"
}
],
"source": "AFFECTED_FIELD",
"strategy": "StandaloneSingleVersion"
}
]
},
{
"extracted_events": [
{
"range": [
{
"introduced": "10.8.0"
},
{
"last_affected": "10.8.3"
},
{
"introduced": "10.5.0"
},
{
"last_affected": "10.5.8"
},
{
"introduced": "9.11.0"
},
{
"last_affected": "9.11.17"
},
{
"introduced": "10.9.0"
},
{
"last_affected": "10.9.2"
}
],
"source": "AFFECTED_FIELD",
"strategy": "StandardRange"
}
]
}
],
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/49xxx/CVE-2025-49222.json"
}
},
"related_cves": [
{
"value": "CVE-2025-49222",
"evidence": "/id"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 512504,
"published_at": "2025-08-21T07:59:45.057+00:00"
}