Vulnerability Description
Discourse is an open-source discussion platform. Prior to version 3.4.4 of the `stable` branch, version 3.5.0.beta5 of the `beta` branch, and version 3.5.0.beta6-dev of the `tests-passed` branch, Codepen is present in the default `allowed_iframes` site setting, and it can potentially auto-run arbitrary JS in the iframe scope, which is unintended. This issue is patched in version 3.4.4 of the `stable` branch, version 3.5.0.beta5 of the `beta` branch, and version 3.5.0.beta6-dev of the `tests-passed` branch. As a workaround, the Codepen prefix can be removed from a site's `allowed_iframes`.
CVSS Score
CRITICAL
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Discourse | Discourse | < 3.4.4 |
Related Weaknesses (CWE)
References
FAQ
What is CVE-2025-48877?
CVE-2025-48877 is a vulnerability with a CVSS score of 9.8 (CRITICAL). Discourse is an open-source discussion platform. Prior to version 3.4.4 of the `stable` branch, version 3.5.0.beta5 of the `beta` branch, and version 3.5.0.beta6-dev of the `tests-passed` branch, Code...
How severe is CVE-2025-48877?
CVE-2025-48877 has been rated CRITICAL with a CVSS base score of 9.8/10. This is considered a critical vulnerability requiring immediate attention.
Is there a patch for CVE-2025-48877?
Check the references section above for vendor advisories and patch information. Affected products include: Discourse Discourse.