What’s Vulnerable › Vulnerabilities
CVE-2025-48062: Discourse vulnerable to HTML injection when inviting to topic via email
- Severity: medium (CVSS 6.1 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 0.3% probability of exploitation in the next 30 days
- Public exploit or detection template: none known
- Published: 2025-06-09 · updated 2026-06-17
- Weakness: CWE-79
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, certain invites via email may result in HTML injection in the email body if the topic title includes HTML. This includes inviting someone (without an account) to a PM and inviting someone (without an account) to a topic with a custom message. 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. This can be worked around if the relevant templates are overridden without `{topic_title}`.
Affected products
- discourse: before 3.4.4; before 3.5.0; 3.5.0-beta1, 3.5.0-beta2, 3.5.0-beta3, 3.5.0-beta4 — fixed in 3.4.4, 3.5.0
How to fix
Upgrade to a fixed version: discourse 3.4.4, 3.5.0. Check the vendor advisory for mitigations.
References
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