High
CVE-2026-6961: Path traversal via unsanitized FileInfo.Name in Mattermost federation sync
Type: advisorySources: OSV
Mattermost versions 11.6.x <= 11.6.1, 11.5.x <= 11.5.4, 10.11.x <= 10.11.15, 10.11.x <= 10.11.16 Mattermost fails to sanitize FileInfo.Name received from federated peers during shared channel file sync, which allows an attacker who controls a federated server to write files to arbitrary locations within the target server's filestore via path traversal sequences in the filename field.. Mattermost Advisory ID: MMSA-2026-00661
- Products
- Not specified
- Affected versions
- Not specified
- Fixed versions
- Not specified
- CVEs
- CVE-2026-6961
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 3 Nov 2026, 07:56 UTC · Revision 1
Source evidence
CVE-2026-6961: Path traversal via unsanitized FileInfo.Name in Mattermost federation sync
core-osv · Original sourcePublished 12 Jun 2026, 15:56 UTC
Mattermost versions 11.6.x <= 11.6.1, 11.5.x <= 11.5.4, 10.11.x <= 10.11.15, 10.11.x <= 10.11.16 Mattermost fails to sanitize FileInfo.Name received from federated peers during shared channel file sync, which allows an attacker who controls a federated server to write files to arbitrary locations within the target server's filestore via path traversal sequences in the filename field.. Mattermost Advisory ID: MMSA-2026-00661
osv:CVE-2026-6961
Complete source record
{
"id": "c98f3f71da3201720169038a94e71012d4a8828612e7da2425e10b316c3dbc97",
"url": "https://osv.dev/vulnerability/CVE-2026-6961",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "CVE-2026-6961: Path traversal via unsanitized FileInfo.Name in Mattermost federation sync",
"summary": "Mattermost versions 11.6.x <= 11.6.1, 11.5.x <= 11.5.4, 10.11.x <= 10.11.15, 10.11.x <= 10.11.16 Mattermost fails to sanitize FileInfo.Name received from federated peers during shared channel file sync, which allows an attacker who controls a federated server to write files to arbitrary locations within the target server's filestore via path traversal sequences in the filename field.. Mattermost Advisory ID: MMSA-2026-00661",
"evidence": "osv:CVE-2026-6961",
"products": [],
"severity": "high",
"structured": {
"id": "CVE-2026-6961",
"aliases": [
"CVE-2026-6961",
"GHSA-8qq9-cqj8-82w4",
"GO-2026-6281"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:N/I:H/A:L"
}
],
"affected": [
{
"ranges": [
{
"repo": "https://github.com/mattermost/mattermost",
"type": "GIT",
"events": [
{
"introduced": "5b955468ea1ea8b56c0fb10feb258a36a767d7bb"
},
{
"fixed": "202d125afa87fe39611686850fd82590c99ca344"
},
{
"introduced": "9f2616376582893035a7e3cb38b0fab648bba4e8"
},
{
"fixed": "d5f29c8ebbeb04460d16d9e2635ce50deeb78428"
},
{
"introduced": "d4f4e78835e86e2e76f76bfe797623076f5c9835"
},
{
"fixed": "1ce2484a00c9821ee19708d2c46720e4855033a9"
}
],
"database_specific": {
"extracted_events": [
{
"cpe": "cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*",
"range": [
{
"introduced": "10.11.0"
},
{
"fixed": "10.11.17"
}
],
"source": "CPE_RANGE"
},
{
"cpe": "cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*",
"range": [
{
"introduced": "11.5.0"
},
{
"fixed": "11.5.5"
}
],
"source": "CPE_RANGE"
},
{
"cpe": "cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*",
"range": [
{
"introduced": "11.6.0"
},
{
"fixed": "11.6.2"
}
],
"source": "CPE_RANGE"
}
]
}
}
],
"versions": [
"v10.11.15-rc1",
"v10.11.15",
"v11.5.4",
"v11.6.1-rc1",
"v11.6.1",
"v11.5.3",
"v10.11.14",
"v11.5.2-rc3",
"v11.5.2",
"v11.6.0",
"v10.11.14-rc1",
"v11.5.0",
"v11.5.2-rc2",
"v11.5.2-rc1",
"v10.11.13",
"v11.5.1",
"v10.11.13-rc1",
"v10.11.12",
"v10.11.11-rc2",
"v10.11.11",
"v10.11.11-rc1",
"v10.11.10",
"v10.11.9",
"v10.11.9-rc1",
"v10.11.8",
"v10.11.7",
"v10.11.6",
"v10.11.5",
"v10.11.4-rc3",
"v10.11.4",
"v10.11.4-rc2",
"v10.11.4-rc1",
"v10.11.3",
"v10.11.2-rc2",
"v10.11.2",
"v10.11.2-rc1",
"v10.11.1",
"v10.11.1-rc1",
"v10.11.0-rc3",
"v10.11.0",
"mattermost-redux@10.11.0",
"@mattermost/types@10.11.0",
"@mattermost/client@10.11.0"
],
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-6961.json"
}
}
],
"modified": "2026-10-28T02:30:26.896674215Z",
"provider": "osv",
"references": [
"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/6xxx/CVE-2026-6961.json",
"https://mattermost.com/security-updates",
"https://nvd.nist.gov/vuln/detail/CVE-2026-6961"
],
"provider_metadata": {
"cwe_ids": [
"CWE-22"
],
"cna_assigner": "Mattermost",
"unresolved_ranges": [
{
"extracted_events": [
{
"range": [
{
"introduced": "11.6.0"
},
{
"last_affected": "11.6.1"
},
{
"introduced": "11.5.0"
},
{
"last_affected": "11.5.4"
},
{
"introduced": "10.11.0"
},
{
"last_affected": "10.11.15"
},
{
"introduced": "10.11.0"
},
{
"last_affected": "10.11.16"
}
],
"source": "AFFECTED_FIELD",
"strategy": "StandardRange"
}
]
}
],
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/6xxx/CVE-2026-6961.json"
}
},
"related_cves": [
{
"value": "CVE-2026-6961",
"evidence": "/id"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 493563,
"published_at": "2026-06-12T15:56:17.364+00:00"
}