Discourse improperly sanitized user input leads to XSS
Priority LOW 29CWE-79Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Cross-site scripting
- Confidentiality · integrity · availability
- Low · Low · Low
- 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. Improperly sanitized user input could lead to an XSS vulnerability in some situations. This vulnerability only affects Discourse instances which have disabled the default Content Security Policy. The vulnerability is patched in 3.1.5 and 3.2.0.beta5. As a workaround, ensure Content Security Policy is enabled and does not include `unsafe-inline`.
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00487 42nd percentileScored 2026-11-07
Fix Fixed discourse (discourse): 3.1.5, 3.2.0.beta5
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
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| discourse | discourse | before 3.1.5; 3.2.0.beta1 to before 3.2.0.beta5 | 3.1.5, 3.2.0.beta5 | Patch available | CNA |
- discourse Vendordiscourse Affected before 3.1.5; 3.2.0.beta1 to before 3.2.0.beta5 Fixed in 3.1.5, 3.2.0.beta5 Patch available CNA
CPE configurations NVD · 6
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:discourse:discourse:*:*:*:*:stable:*:*:* | before 3.1.5 | Vulnerable | discourse |
| cpe:2.3:a:discourse:discourse:*:*:*:*:beta:*:*:* | before 3.2.0 | Vulnerable | discourse |
| cpe:2.3:a:discourse:discourse:3.2.0:beta1:*:*:beta:*:*:* | 3.2.0 beta1 | Vulnerable | discourse |
| cpe:2.3:a:discourse:discourse:3.2.0:beta2:*:*:beta:*:*:* | 3.2.0 beta2 | Vulnerable | discourse |
| cpe:2.3:a:discourse:discourse:3.2.0:beta3:*:*:beta:*:*:* | 3.2.0 beta3 | Vulnerable | discourse |
| cpe:2.3:a:discourse:discourse:3.2.0:beta4:*:*:beta:*:*:* | 3.2.0 beta4 | Vulnerable | discourse |
- cpe:2.3:a:discourse:discourse:*:*:*:*:stable:*:*:* Versions before 3.1.5 Vulnerable ·discourse
- cpe:2.3:a:discourse:discourse:*:*:*:*:beta:*:*:* Versions before 3.2.0 Vulnerable ·discourse
- cpe:2.3:a:discourse:discourse:3.2.0:beta1:*:*:beta:*:*:* Versions 3.2.0 beta1 Vulnerable ·discourse
- cpe:2.3:a:discourse:discourse:3.2.0:beta2:*:*:beta:*:*:* Versions 3.2.0 beta2 Vulnerable ·discourse
- cpe:2.3:a:discourse:discourse:3.2.0:beta3:*:*:beta:*:*:* Versions 3.2.0 beta3 Vulnerable ·discourse
- cpe:2.3:a:discourse:discourse:3.2.0:beta4:*:*:beta:*:*:* Versions 3.2.0 beta4 Vulnerable ·discourse
Remediation
- Fix · CNA discourse (discourse) Fixed in 3.1.5, 3.2.0.beta5
Timeline
- 2026-10-02 Threatist record created from CVE-2024-23834
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