{"cve":"CVE-2026-27166","nvd":{"published":"2026-03-19T21:17:08.740","modified":"2026-06-17T10:26:46.800","status":"Analyzed","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.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N","score":5.4},"cwes":["CWE-80"],"references":["https://github.com/discourse/discourse/commit/c4762a4fac2f61f52f325396b11d3aeb955ea925","https://github.com/discourse/discourse/security/advisories/GHSA-h653-cq78-vjj2"],"products":["discourse:discourse"],"source":"nvd","synced_at":"2026-10-19T22:26:19.218427112+00:00"},"epss":{"cve":"CVE-2026-27166","score":0.00194,"percentile":0.09116,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}