CVE-2021-43850

mediumpriority · track · 27EPSS 0.008 · 57 %ileEUUS
grimoire priorityP3 · Track
Exploitable?
—
no known exploitation
Likely / severe?
0.83% (57th) EPSS
CVSS 4 · medium
Is it mine?
5 products
Check your exposure
Who says so?
4 sources
cnnvd · enisa_euvd · osv · nvd

EPSS · scored 2026-10-27

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.

01

cvss

Technical severity, 0–10. One row per scoring source.

6.8
010

base score 0–10 · higher = more severe · hover a vector to decode

v2.04mediumAV:N/AC:L/Au:S/C:N/I:N/A:Pprimary · NVD / NIST USexploitability 8 · impact 2.9
v3.16.8mediumCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:N/I:N/A:Hprimary · NVD / NIST USexploitability 2.3 · impact 4
v3.16.8mediumCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:N/I:N/A:Hsecondary · ENISA EU
v3.16.8mediumCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:N/I:N/A:Hsecondary · security-advisories@github.comexploitability 2.3 · impact 4
v3.16.2mediumCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:N/I:N/A:H/E:Usecondary · CVSS-BT (t0sche)
02

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-20US
03

affected products (5)

Products and version ranges known to be affected.

04

advisories (1)

Vendor and ecosystem advisories describing this.

  • BIT-discourse-2021-43850Denial of Service in discourse2024-03-06vendor · osvUS

    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.

05

also known as (3)

Other names and identifiers for this entity.

06

sources

Which sources assert this record, and when.

cnnvdenisa_euvdosvnvdNVDCVE.orgMITRE
published 2022-01-04modified 2026-06-17
07

references (7)

External citations — patches, advisories, analysis.

scry

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