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TI-2021-15508 Aliases CVE-2021-37633

XSS via d-popover and d-html-popover attribute

Priority LOW 34CWE-79Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
Required
Attack complexity
Low
Impact type
Cross-site scripting
Confidentiality · integrity · availability
High · None · None
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-79.

Summary

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.

Why it matters now

EPSS 0.00758 55th percentileScored 2026-11-07
Fix Fixed discourse (discourse): 2.7.8

SSVC decision points

Not available: CISA has not published SSVC decision points for this record.

Affected products

VendorProductAffected versionsFixed inStatusSource
discoursediscoursebefore 2.7.82.7.8Patch availableCNA
  • discourse Vendordiscourse Affected before 2.7.8 Fixed in 2.7.8 Patch available CNA

CPE configurations NVD · 3

CPEVersionsRoleVendor
cpe:2.3:a:discourse:discourse:*:*:*:*:*:*:*:*before 2.7.8Vulnerablediscourse
cpe:2.3:a:discourse:discourse:2.8.0:beta2:*:*:*:*:*:*2.8.0 beta2Vulnerablediscourse
cpe:2.3:a:discourse:discourse:2.8.0:beta3:*:*:*:*:*:*2.8.0 beta3Vulnerablediscourse
  • cpe:2.3:a:discourse:discourse:*:*:*:*:*:*:*:* Versions before 2.7.8 Vulnerable ·discourse
  • cpe:2.3:a:discourse:discourse:2.8.0:beta2:*:*:*:*:*:* Versions 2.8.0 beta2 Vulnerable ·discourse
  • cpe:2.3:a:discourse:discourse:2.8.0:beta3:*:*:*:*:*:* Versions 2.8.0 beta3 Vulnerable ·discourse

Remediation

  • Fix · CNA discourse (discourse) Fixed in 2.7.8

Timeline

  1. 2026-10-02 Threatist record created from CVE-2021-37633

References

Patch 1

Advisory 1

  • TI-2021-19656 Denial of Service in discourse CVSS 3.1MEDIUM 6.8
  • TI-2024-36150 Potential Backup file leaked via Nginx in Discourse CVSS 3.1HIGH 7.5
  • TI-2021-18002 RCE via malicious SNS subscription payload CVSS 3.1CRITICAL 10.0
  • TI-2026-24651 Discourse: Open redirect via `sso_destination_url` cookie in `enter` CVSS 4.0MEDIUM 5.1
  • TI-2026-22278 Discourse leaks private topic title and post excerpt via user action API endpoint CVSS 4.0HIGH 8.7
  • TI-2023-24152 Unauthenticated access to new private chat messages in Discourse CVSS 3.1HIGH 7.5
See all 262 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences