CVE-2026-27166
Last modified
CVE-2026-27166 is a medium-severity vulnerability rated 5.4/10 on the CVSS scale. Discourse is an open source discussion platform. Prior to versions 2026.3.0-latest.1, 2026.2.1 and 2026.1.2, insufficient cleanup in the default Codepen allowed iframes value allows an attacker to trick a user into changing the URL of the main page. EPSS estimates a 0.19% chance of exploitation in the next 30 days.
Description
Discourse is an open source discussion platform. Prior to versions 2026.3.0-latest.1, 2026.2.1 and 2026.1.2, insufficient cleanup in the default Codepen allowed iframes value allows an attacker to trick a user into changing the URL of the main page. This issue has been fixed in versions 2026.3.0-latest.1, 2026.2.1 and 2026.1.2. To workaround this issue, remove Codepen from the list of allowed iframes.
Metrics
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
Weakness Enumeration
Affected Software
| Vendor | Product | Versions |
|---|---|---|
| Discourse | Discourse | < 2026.3.0 |
| Discourse | Discourse | >= 2026.1.0, < 2026.1.2 |
| Discourse | Discourse | >= 2026.2.0, < 2026.2.1 |
| Discourse | Discourse | 2026.3.0 |
References
Timeline
- Published
- Last Modified
- Status
- Analyzed
Frequently Asked Questions
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How Strix Helps
- How Strix found a critical auth bypass in etcdStrix autonomously discovered a critical authentication bypass in etcd, later designated CVE-2026-33413.
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