Discourse allows self-XSS through malicious composer message
Priority LOW 34CWE-79Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- Low
- User interaction
- Required
- Attack complexity
- High
- Impact type
- Cross-site scripting
- Confidentiality · integrity · availability
- High · High · High
- 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 messaging platform. In versions 2.8.10 and prior on the `stable` branch and versions 2.9.0.beta11 and prior on the `beta` and `tests-passed` branches, users composing malicious messages and navigating to drafts page could self-XSS. This vulnerability can lead to a full XSS on sites which have modified or disabled Discourse’s default Content Security Policy. This issue is patched in the latest stable, beta and tests-passed versions of Discourse.
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00492 42nd 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
- Total
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 | up to 2.8.10; 2.9.0.beta1 – 2.9.0.beta11 | — | No fix listed | CNA |
- discourse Vendordiscourse Affected up to 2.8.10; 2.9.0.beta1 – 2.9.0.beta11 Fixed in — No fix listed CNA
CPE configurations NVD · 11
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:discourse:discourse:*:*:*:*:*:*:*:* | up to 2.8.10 | Vulnerable | discourse |
| cpe:2.3:a:discourse:discourse:2.9.0:beta1:*:*:*:*:*:* | 2.9.0 beta1 | Vulnerable | discourse |
| cpe:2.3:a:discourse:discourse:2.9.0:beta10:*:*:*:*:*:* | 2.9.0 beta10 | Vulnerable | discourse |
| cpe:2.3:a:discourse:discourse:2.9.0:beta11:*:*:*:*:*:* | 2.9.0 beta11 | Vulnerable | discourse |
| cpe:2.3:a:discourse:discourse:2.9.0:beta2:*:*:*:*:*:* | 2.9.0 beta2 | Vulnerable | discourse |
| cpe:2.3:a:discourse:discourse:2.9.0:beta3:*:*:*:*:*:* | 2.9.0 beta3 | Vulnerable | discourse |
| cpe:2.3:a:discourse:discourse:2.9.0:beta4:*:*:*:*:*:* | 2.9.0 beta4 | Vulnerable | discourse |
| cpe:2.3:a:discourse:discourse:2.9.0:beta5:*:*:*:*:*:* | 2.9.0 beta5 | Vulnerable | discourse |
| cpe:2.3:a:discourse:discourse:2.9.0:beta6:*:*:*:*:*:* | 2.9.0 beta6 | Vulnerable | discourse |
| cpe:2.3:a:discourse:discourse:2.9.0:beta7:*:*:*:*:*:* | 2.9.0 beta7 | Vulnerable | discourse |
- cpe:2.3:a:discourse:discourse:*:*:*:*:*:*:*:* Versions up to 2.8.10 Vulnerable ·discourse
- cpe:2.3:a:discourse:discourse:2.9.0:beta1:*:*:*:*:*:* Versions 2.9.0 beta1 Vulnerable ·discourse
- cpe:2.3:a:discourse:discourse:2.9.0:beta10:*:*:*:*:*:* Versions 2.9.0 beta10 Vulnerable ·discourse
- cpe:2.3:a:discourse:discourse:2.9.0:beta11:*:*:*:*:*:* Versions 2.9.0 beta11 Vulnerable ·discourse
- cpe:2.3:a:discourse:discourse:2.9.0:beta2:*:*:*:*:*:* Versions 2.9.0 beta2 Vulnerable ·discourse
- cpe:2.3:a:discourse:discourse:2.9.0:beta3:*:*:*:*:*:* Versions 2.9.0 beta3 Vulnerable ·discourse
- cpe:2.3:a:discourse:discourse:2.9.0:beta4:*:*:*:*:*:* Versions 2.9.0 beta4 Vulnerable ·discourse
- cpe:2.3:a:discourse:discourse:2.9.0:beta5:*:*:*:*:*:* Versions 2.9.0 beta5 Vulnerable ·discourse
- cpe:2.3:a:discourse:discourse:2.9.0:beta6:*:*:*:*:*:* Versions 2.9.0 beta6 Vulnerable ·discourse
- cpe:2.3:a:discourse:discourse:2.9.0:beta7:*:*:*:*:*:* Versions 2.9.0 beta7 Vulnerable ·discourse
Remediation
No fixed version listed by the sources yet.
Timeline
- 2026-10-02 Threatist record created from CVE-2022-46148
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