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TI-2024-36047 Aliases CVE-2024-53851

Partial denial of service via inline oneboxes in Discourse

Priority LOW 29CWE-400Published · Updated

Key facts

Attack vector
Network
Privileges required
Low
User interaction
None
Attack complexity
Low
Impact type
Denial of service
Confidentiality · integrity · availability
None · None · High
Fix status
No fix listed

Attack profile from CVSS 3.1 · NVD. Fix status from CNA. Impact type from CWE-400.

Summary

Discourse is an open source platform for community discussion. In affected versions the endpoint for generating inline oneboxes for URLs wasn't enforcing limits on the number of URLs that it accepted, allowing a malicious user to inflict denial of service on some parts of the app. This vulnerability is only exploitable by authenticated users. This issue has been patched in the latest stable, beta and tests-passed versions of Discourse. Users are advised to upgrade. Users unable to upgrade should turn off the `enable inline onebox on all domains` site setting and remove all entries from the `allowed inline onebox domains` site setting.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00455 39th percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
discoursediscoursestable: <= 3.3.2; beta: <= 3.4.0.beta3; tests-passed: <= 3.4.0.beta3—No fix listedCNA
  • discourse Vendordiscourse Affected stable: <= 3.3.2; beta: <= 3.4.0.beta3; tests-passed: <= 3.4.0.beta3 Fixed in — No fix listed CNA

CPE configurations NVD · 5

CPEVersionsRoleVendor
cpe:2.3:a:discourse:discourse:*:*:*:*:stable:*:*:*before 3.3.3Vulnerablediscourse
cpe:2.3:a:discourse:discourse:*:*:*:*:beta:*:*:*before 3.4.0Vulnerablediscourse
cpe:2.3:a:discourse:discourse:3.4.0:beta1:*:*:beta:*:*:*3.4.0 beta1Vulnerablediscourse
cpe:2.3:a:discourse:discourse:3.4.0:beta2:*:*:beta:*:*:*3.4.0 beta2Vulnerablediscourse
cpe:2.3:a:discourse:discourse:3.4.0:beta3:*:*:beta:*:*:*3.4.0 beta3Vulnerablediscourse
  • cpe:2.3:a:discourse:discourse:*:*:*:*:stable:*:*:* Versions before 3.3.3 Vulnerable ·discourse
  • cpe:2.3:a:discourse:discourse:*:*:*:*:beta:*:*:* Versions before 3.4.0 Vulnerable ·discourse
  • cpe:2.3:a:discourse:discourse:3.4.0:beta1:*:*:beta:*:*:* Versions 3.4.0 beta1 Vulnerable ·discourse
  • cpe:2.3:a:discourse:discourse:3.4.0:beta2:*:*:beta:*:*:* Versions 3.4.0 beta2 Vulnerable ·discourse
  • cpe:2.3:a:discourse:discourse:3.4.0:beta3:*:*:beta:*:*:* Versions 3.4.0 beta3 Vulnerable ·discourse

Remediation

No fixed version listed by the sources yet.

Timeline

  1. 2026-10-02 Threatist record created from CVE-2024-53851

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