Cross-site Scripting (XSS) via chat excerpts when content security policy (CSP) disabled in Discourse
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Cross-site scripting
- Confidentiality · integrity · availability
- Low · None · Low
- Fix status
- No fix listed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-79.
Summary
Discourse is an open source platform for community discussion. An attacker can execute arbitrary JavaScript on users' browsers by sending a maliciously crafted chat message and replying to it. This issue only affects sites with CSP disabled. This problem is patched in the latest version of Discourse. All users are advised to upgrade. Users unable to upgrade should ensure CSP is enabled on the forum. Users who do upgrade should also consider enabling a CSP as well as a proactive measure.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- Yes
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| discourse | discourse | stable: < 3.3.2; tests-passed: < 3.4.0.beta2 | — | No fix listed | CNA |
- discourse Vendordiscourse Affected stable: < 3.3.2; tests-passed: < 3.4.0.beta2 Fixed in — No fix listed CNA
Remediation
No fixed version listed by the sources yet.
Timeline
- 2026-10-02 Threatist record created from CVE-2024-47772
References
More Discourse vulnerabilities
- 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
Sources
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences