High
Security advisory
An issue was discovered in Mattermost Server before 5.23.0. Large webhook requests allow attackers to cause a denial of service (infinite loop), aka MMSA-2020-0021.
- Products
- Not specified
- Affected versions
- Not specified
- Fixed versions
- Not specified
- CVEs
- CVE-2020-14447
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 1 Nov 2026, 06:51 UTC · Revision 1
Source evidence
An issue was discovered in Mattermost Server before 5.23.0. Large webhook requests allow attackers to cause a denial of service (infinite loop), aka MMSA-2020-0021.
osv:CVE-2020-14447
Complete source record
{
"id": "bdb75244878df01ce37b72535c5bb875ebadcba5f99697585ee35e23c0e5357d",
"url": "https://osv.dev/vulnerability/CVE-2020-14447",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "CVE-2020-14447",
"summary": "An issue was discovered in Mattermost Server before 5.23.0. Large webhook requests allow attackers to cause a denial of service (infinite loop), aka MMSA-2020-0021.",
"evidence": "osv:CVE-2020-14447",
"products": [],
"severity": "high",
"structured": {
"id": "CVE-2020-14447",
"aliases": [
"BIT-mattermost-2020-14447",
"CVE-2020-14447"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
}
],
"affected": [
{
"ranges": [
{
"repo": "https://github.com/mattermost/mattermost",
"type": "GIT",
"events": [
{
"introduced": "0"
},
{
"fixed": "ed1576d007a09b07574b18784b9eabb3d8c9db53"
}
],
"database_specific": {
"extracted_events": [
{
"cpe": "cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*",
"range": [
{
"introduced": "0"
},
{
"fixed": "5.23.0"
}
],
"source": "CPE_RANGE"
}
]
}
}
],
"versions": [
"v5.23.0-rc3",
"v5.23.0-rc2",
"v5.23.0-rc1",
"v5.23-rc1",
"v5.22.0-rc3",
"v5.22.0-rc2",
"v5.22.0-rc1",
"v5.2.0-rc2",
"v5.2.0-rc1",
"v5.1.0-rc1",
"v5.0.0-rc1",
"v4.10.0-rc1",
"v4.9.0-rc1",
"v4.8.0-rc1",
"v4.7.0-rc1",
"v4.6.0-rc2",
"v4.6.0-rc1",
"v4.5.0-rc1",
"v4.4.0-rc1",
"v4.3.0-rc1",
"v4.2.0-rc1",
"v0.5.0"
],
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2020-14447.json"
}
}
],
"modified": "2026-10-24T10:30:45.346873571Z",
"provider": "osv",
"references": [
"https://mattermost.com/security-updates/"
],
"provider_metadata": {}
},
"related_cves": [
{
"value": "CVE-2020-14447",
"evidence": "/id"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 436110,
"published_at": "2020-06-19T14:15:11.183+00:00"
}