Medium
Security advisory
Rocket.Chat before 3.11, 3.10.5, 3.9.7, 3.8.8 is vulnerable to persistent cross-site scripting (XSS) using nested markdown tags allowing a remote attacker to inject arbitrary JavaScript in a message. This flaw leads to arbitrary file read and RCE on Rocket.Chat desktop app.
- Products
- Not specified
- Affected versions
- Not specified
- Fixed versions
- Not specified
- CVEs
- CVE-2021-22886
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 31 Oct 2026, 11:39 UTC · Revision 1
Source evidence
Rocket.Chat before 3.11, 3.10.5, 3.9.7, 3.8.8 is vulnerable to persistent cross-site scripting (XSS) using nested markdown tags allowing a remote attacker to inject arbitrary JavaScript in a message. This flaw leads to arbitrary file read and RCE on Rocket.Chat desktop app.
osv:CVE-2021-22886
Complete source record
{
"id": "5244e32785561b88538ae6665fe52596ec9919ba4b1950dc59f1c10c70ffd2a3",
"url": "https://osv.dev/vulnerability/CVE-2021-22886",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "CVE-2021-22886",
"summary": "Rocket.Chat before 3.11, 3.10.5, 3.9.7, 3.8.8 is vulnerable to persistent cross-site scripting (XSS) using nested markdown tags allowing a remote attacker to inject arbitrary JavaScript in a message. This flaw leads to arbitrary file read and RCE on Rocket.Chat desktop app.",
"evidence": "osv:CVE-2021-22886",
"products": [],
"severity": "medium",
"structured": {
"id": "CVE-2021-22886",
"aliases": [
"CVE-2021-22886"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N"
}
],
"affected": [
{
"ranges": [
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"repo": "https://github.com/rocketchat/rocket.chat",
"type": "GIT",
"events": [
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{
"fixed": "95ed038f24ca3a43dc4e2b899197b53477d8f40e"
},
{
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"source": "CPE_RANGE"
},
{
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{
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"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2021-22886.json"
}
}
],
"modified": "2026-10-20T10:54:31.279491294Z",
"provider": "osv",
"references": [
"https://docs.rocket.chat/guides/security/security-updates",
"https://hackerone.com/reports/1014459",
"https://github.com/RocketChat/Rocket.Chat/pull/20430"
],
"provider_metadata": {
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"source": "CPE_STRING"
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}
},
"related_cves": [
{
"value": "CVE-2021-22886",
"evidence": "/id"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 385486,
"published_at": "2021-03-26T19:15:11.913+00:00"
}