# CVE-2025-48877

## Summary

- **CVE ID:** CVE-2025-48877
- **Severity:** HIGH
- **CVSS Score:** 8.1 (CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U)
- **CWE:** CWE-1038
- **Published:** Jun 9, 2025
- **Last Modified:** Mar 13, 2026

## 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`.

## Affected Products

- discourse — discourse (< 3.4.4)
- discourse — discourse (< 3.5.0.beta5)
- discourse — discourse (< 3.5.0.beta6-dev)

## References

- [CNA](https://github.com/discourse/discourse/security/advisories/GHSA-cm93-6m2m-cjcv)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.38%
- **EPSS Percentile:** 31.3

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-10._