CVE-2021-37633

mediumpriority · track · 24EPSS 0.008 · 55 %ileEUUS

grimoire priorityP3 · Track

Exploitable?

—

no known exploitation

Likely / severe?

0.76% (55th) EPSS

CVSS 4.3 · medium

Is it mine?

4 products

Check your exposure

Who says so?

4 sources

cnnvd · enisa_euvd · osv · nvd

EPSS · scored 2026-10-27

Discourse is an open source discussion platform. In versions prior to 2.7.8 rendering of d-popover tooltips can be susceptible to XSS attacks. This vulnerability only affects sites which have modified or disabled Discourse's default Content Security Policy. This issue is patched in the latest `stable` 2.7.8 version of Discourse. As a workaround users may ensure that the Content Security Policy is enabled, and has not been modified in a way which would make it more vulnerable to XSS attacks.

cvss

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

7.4

010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 4.3–7.4

v2.04.3mediumAV:N/AC:M/Au:N/C:N/I:P/A:Nprimary · NVD / NIST USexploitability 8.6 · impact 2.9

v3.16.1mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:Nprimary · NVD / NIST USexploitability 2.8 · impact 2.7

v3.17.4highCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:N/A:Nsecondary · ENISA EU

v3.17.4highCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:N/A:Nsecondary · security-advisories@github.comexploitability 2.8 · impact 4

v3.15.6mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N/E:Usecondary · CVSS-BT (t0sche)

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-79USprimary

affected products (4)

Products and version ranges known to be affected.

discourse discourse≤ < 2.7.8enisa_euvdEU
discourse discourse< 2.7.8nvdUScpe:2.3:a:discourse:discourse:*:*:*:*:*:*:*:*
discourse discourse= 2.8.0nvdUScpe:2.3:a:discourse:discourse:*:*:*:*:*:*:*:*
Bitnami discourse< 2.7.8osvUSpkg:bitnami/discourse

advisories (1)

Vendor and ecosystem advisories describing this.

BIT-discourse-2021-37633XSS via d-popover and d-html-popover attribute2024-03-06vendor · osvUS
Discourse is an open source discussion platform. In versions prior to 2.7.8 rendering of d-popover tooltips can be susceptible to XSS attacks. This vulnerability only affects sites which have modified or disabled Discourse's default Content Security Policy. This issue is patched in the latest `stable` 2.7.8 version of Discourse. As a workaround users may ensure that the Content Security Policy is enabled, and has not been modified in a way which would make it more vulnerable to XSS attacks.

also known as (3)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd osv nvd NVD CVE.org MITRE

published 2021-08-09modified 2026-06-17

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+53008 more

references (6)

External citations — patches, advisories, analysis.

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