Medium
Security advisory
Discourse is an open source platform for community discussion. In affected versions admins users can trigger a Denial of Service attack via the `/message-bus/_diagnostics` path. The impact of this vulnerability is greater on multisite Discourse instances (where multiple forums are served from a single application server) where any admin user on any of the forums are able to visit the `/message-bus/_diagnostics` path. The problem has been patched. Please upgrade to 2.8.0.beta10 or 2.7.12. No workarounds for this issue exist.
- Products
- Not specified
- Affected versions
- Not specified
- Fixed versions
- Not specified
- CVEs
- CVE-2021-43850
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 31 Oct 2026, 12:01 UTC · Revision 1
Source evidence
Discourse is an open source platform for community discussion. In affected versions admins users can trigger a Denial of Service attack via the `/message-bus/_diagnostics` path. The impact of this vulnerability is greater on multisite Discourse instances (where multiple forums are served from a single application server) where any admin user on any of the forums are able to visit the `/message-bus/_diagnostics` path. The problem has been patched. Please upgrade to 2.8.0.beta10 or 2.7.12. No workarounds for this issue exist.
osv:CVE-2021-43850
Complete source record
{
"id": "9af0bf3e1eb0948fd4d3784bbe42b51c311a55e4c333efd6f10331a432e32be2",
"url": "https://osv.dev/vulnerability/CVE-2021-43850",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "CVE-2021-43850",
"summary": "Discourse is an open source platform for community discussion. In affected versions admins users can trigger a Denial of Service attack via the `/message-bus/_diagnostics` path. The impact of this vulnerability is greater on multisite Discourse instances (where multiple forums are served from a single application server) where any admin user on any of the forums are able to visit the `/message-bus/_diagnostics` path. The problem has been patched. Please upgrade to 2.8.0.beta10 or 2.7.12. No workarounds for this issue exist.",
"evidence": "osv:CVE-2021-43850",
"products": [],
"severity": "medium",
"structured": {
"id": "CVE-2021-43850",
"aliases": [
"BIT-discourse-2021-43850",
"CVE-2021-43850",
"GHSA-59jr-pj65-qmvr"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:N/I:N/A:H"
}
],
"affected": [
{
"ranges": [
{
"repo": "https://github.com/discourse/discourse",
"type": "GIT",
"events": [
{
"introduced": "0"
},
{
"fixed": "81b398030ef4389a4a8192a287bc1b26203d58e0"
},
{
"introduced": "05c1d3c9cdd7f3e365bedc397dd92a7e7bc2c40f"
},
{
"last_affected": "c4d3b6556d750b9157a766ee370f2b4945dbb986"
},
{
"fixed": "7a8ec129fb54f188b2da6588c9d24d3a36eb0d39"
}
],
"database_specific": {
"extracted_events": [
{
"cpe": "cpe:2.3:a:discourse:discourse:*:*:*:*:*:*:*:*",
"range": [
{
"introduced": "0"
},
{
"fixed": "2.7.12"
}
],
"source": "CPE_RANGE"
},
{
"cpe": "cpe:2.3:a:discourse:discourse:2.8.0:beta1:*:*:*:*:*:*",
"range": [
{
"introduced": "2.8.0-beta1"
},
{
"last_affected": "2.8.0-beta1"
}
],
"source": "CPE_STRING"
},
{
"cpe": "cpe:2.3:a:discourse:discourse:2.8.0:beta2:*:*:*:*:*:*",
"range": [
{
"introduced": "2.8.0-beta2"
},
{
"last_affected": "2.8.0-beta2"
}
],
"source": "CPE_STRING"
},
{
"cpe": "cpe:2.3:a:discourse:discourse:2.8.0:beta3:*:*:*:*:*:*",
"range": [
{
"introduced": "2.8.0-beta3"
},
{
"last_affected": "2.8.0-beta3"
}
],
"source": "CPE_STRING"
},
{
"cpe": "cpe:2.3:a:discourse:discourse:2.8.0:beta4:*:*:*:*:*:*",
"range": [
{
"introduced": "2.8.0-beta4"
},
{
"last_affected": "2.8.0-beta4"
}
],
"source": "CPE_STRING"
},
{
"cpe": "cpe:2.3:a:discourse:discourse:2.8.0:beta5:*:*:*:*:*:*",
"range": [
{
"introduced": "2.8.0-beta5"
},
{
"last_affected": "2.8.0-beta5"
}
],
"source": "CPE_STRING"
},
{
"cpe": "cpe:2.3:a:discourse:discourse:2.8.0:beta6:*:*:*:*:*:*",
"range": [
{
"introduced": "2.8.0-beta6"
},
{
"last_affected": "2.8.0-beta6"
}
],
"source": "CPE_STRING"
},
{
"cpe": "cpe:2.3:a:discourse:discourse:2.8.0:beta7:*:*:*:*:*:*",
"range": [
{
"introduced": "2.8.0-beta7"
},
{
"last_affected": "2.8.0-beta7"
}
],
"source": "CPE_STRING"
},
{
"cpe": "cpe:2.3:a:discourse:discourse:2.8.0:beta8:*:*:*:*:*:*",
"range": [
{
"introduced": "2.8.0-beta8"
},
{
"last_affected": "2.8.0-beta8"
}
],
"source": "CPE_STRING"
},
{
"cpe": "cpe:2.3:a:discourse:discourse:2.8.0:beta9:*:*:*:*:*:*",
"range": [
{
"introduced": "2.8.0-beta9"
},
{
"last_affected": "2.8.0-beta9"
}
],
"source": "CPE_STRING"
},
{
"range": [
{
"fixed": "7a8ec129fb54f188b2da6588c9d24d3a36eb0d39"
}
],
"source": "REFERENCES_COMMIT"
}
]
}
}
],
"versions": [
"2.8.0-beta1",
"2.8.0-beta2",
"2.8.0-beta3",
"2.8.0-beta4",
"2.8.0-beta5",
"2.8.0-beta6",
"2.8.0-beta7",
"2.8.0-beta8",
"2.8.0-beta9",
"v2.7.11",
"v2.8.0.beta9",
"v2.7.10",
"v2.8.0.beta8",
"v2.7.9",
"v2.8.0.beta7",
"v2.7.8",
"v2.8.0.beta6",
"v2.8.0.beta5",
"v2.7.7",
"v2.7.6",
"v2.8.0.beta4",
"v2.8.0.beta3",
"v2.7.5",
"v2.7.4",
"v2.7.3",
"v2.8.0.beta2",
"v2.7.2",
"v2.7.1",
"v2.7.0",
"v2.8.0.beta1",
"v2.6.7",
"v2.6.6",
"v2.6.5",
"v2.6.4",
"v2.6.3",
"v2.6.2",
"v2.6.1",
"v2.6.0",
"v2.5.5",
"v2.5.4",
"v2.5.3",
"v2.5.2",
"v2.5.1",
"v2.5.0",
"v2.4.5",
"v2.4.4",
"v2.4.3",
"v2.4.2",
"v2.4.1",
"v2.4.0",
"v2.3.10",
"v2.3.9",
"v2.3.8",
"v2.3.7",
"v2.3.6",
"v2.3.5",
"v2.3.4",
"v2.3.3",
"v2.3.2",
"v2.3.1",
"v2.3.0",
"v2.2.6",
"v2.2.5",
"v2.2.4",
"v2.2.3",
"v2.2.2",
"v2.2.1",
"v2.2.0",
"v2.1.8",
"v2.1.7",
"v2.1.6",
"v2.1.5",
"v2.1.4",
"v2.1.3",
"v2.1.2",
"v2.1.1",
"v2.1.0",
"v2.0.5",
"v2.0.4",
"v2.0.3",
"v2.0.2",
"v2.0.1",
"v2.0.0",
"v1.9.7",
"v1.9.6",
"v1.9.5",
"v1.9.4",
"v1.9.3",
"v1.9.2",
"v1.9.1",
"v1.9.0",
"v1.8.11",
"v1.8.10",
"v1.8.9",
"v1.8.8",
"v1.8.7",
"v1.8.6",
"v1.8.5",
"v1.8.4",
"v1.8.3",
"v1.8.2",
"v1.8.1",
"v1.8.0",
"v1.7.10",
"v1.7.9",
"v1.7.8",
"v1.7.7",
"v1.7.6",
"v1.7.5",
"v1.7.4",
"v1.7.3",
"v1.7.2",
"v1.7.1",
"v1.7.0",
"v1.6.10",
"v1.6.9",
"v1.6.8",
"v1.6.7",
"v1.6.6",
"v1.6.5",
"v1.6.4",
"v1.6.3",
"v1.6.2",
"v1.6.1",
"v1.6.0",
"v1.5.4",
"v1.5.3",
"v1.5.2",
"v1.5.1",
"v1.5.0",
"v1.4.7",
"v1.4.6",
"v1.4.5",
"v1.4.4",
"v1.4.3",
"v1.4.2",
"v1.4.1",
"v1.4.0",
"v1.3.5",
"v1.3.4",
"v1.3.3",
"v1.3.2",
"v1.3.1",
"v1.3.0",
"v1.2.4",
"v1.2.3",
"v1.2.2",
"v1.2.1",
"v1.2.0",
"v1.1.3",
"v1.1.2",
"v1.1.1",
"v1.1.0",
"v1.0.4",
"v1.0.3",
"v1.0.2",
"v1.0.1",
"v1.0.0",
"v0.9.9.18",
"v0.9.9.17",
"v0.9.9.16",
"v0.9.9.15",
"v0.9.9.14",
"v0.9.9.13",
"v0.9.9.12",
"v0.9.9.11",
"v0.9.9.10",
"v0.9.9.9",
"v0.9.9.8",
"v0.9.9.7",
"v0.9.9.6",
"v0.9.9.5",
"v0.9.9.4",
"v0.9.9.3",
"v0.9.9.2",
"v0.9.9.1",
"v0.9.8.11",
"v0.9.8.10",
"v0.9.8.9",
"v0.9.8.8",
"v0.9.8.7",
"v0.9.8.6",
"v0.9.8.5",
"v0.9.8.4",
"v0.9.8.3",
"v0.9.8.2",
"v0.9.8.1",
"v0.9.8",
"v0.9.7.9",
"v0.9.7.8",
"v0.9.7.7",
"v0.9.7.6",
"v0.9.7.5",
"v0.9.7.4",
"v0.9.7.3",
"v0.9.7.2",
"v0.9.7.1",
"v0.9.7",
"v0.9.6.4",
"v0.9.6.3",
"v0.9.6.1",
"v0.9.6",
"v0.9.5.2",
"v0.9.5.1",
"v0.9.5",
"v0.9.4",
"v0.9.3",
"v0.9.2.6",
"v0.9.2.5",
"v0.9.2",
"v0.9.1",
"v0.9.0",
"v0.8.9",
"v0.8.8",
"v0.8.7",
"v0.8.6",
"v0.8.5",
"v0.8.4",
"v0.8.3",
"v0.8.2",
"v0.8.1",
"v0.8.0"
],
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2021-43850.json"
}
}
],
"modified": "2026-10-20T10:55:04.547278576Z",
"provider": "osv",
"references": [
"https://github.com/discourse/discourse/commit/7a8ec129fb54f188b2da6588c9d24d3a36eb0d39",
"https://github.com/discourse/discourse/security/advisories/GHSA-59jr-pj65-qmvr"
],
"provider_metadata": {}
},
"related_cves": [
{
"value": "CVE-2021-43850",
"evidence": "/id"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 386831,
"published_at": "2022-01-04T20:15:07.667+00:00"
}