{"cve":"CVE-2026-91132","nvd":{"published":"2026-09-24T17:17:08.723","modified":"2026-09-29T03:17:21.457","status":"Deferred","description":"Discourse is an open-source discussion platform. Prior to 2026.1.8, 2026.6.3, 2026.7.2, and 2026.8.0, sites using wildcard patterns in the allowed_iframes setting could accept a crafted iframe URL whose allowlisted suffix appeared after a URL authority separator. The wildcard origin check matched the allowed domain text, while browser URL parsing selected a different attacker-controlled origin. A user with posting privileges could exploit the flaw through a post or a Onebox oEmbed response and cause an attacker-controlled iframe to be rendered independently of the allowlisted domain. Successful exploitation requires a site-configured wildcard iframe pattern and the ability to create a post or trigger an oEmbed request for an attacker-controlled URL. This issue is fixed in versions 2026.1.8, 2026.6.3, 2026.7.2, and 2026.8.0.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N","score":4.3},"cwes":["CWE-346"],"references":["https://github.com/discourse/discourse/commit/80968704c1acb1d2ea2c6011dbf6c02ff13238e5","https://github.com/discourse/discourse/commit/d5ae0940707f95da5bc4562f7b544243e3103f8a","https://github.com/discourse/discourse/commit/d88e02ceb2eede4d8b851d9fe8aef753f3aa40b9","https://github.com/discourse/discourse/commit/db8064f2a2a2a3feb3308a1c932ac61d950c9e56","https://github.com/discourse/discourse/pull/42882"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:56:02.509636177+00:00"},"epss":{"cve":"CVE-2026-91132","score":0.00136,"percentile":0.03,"date":"2026-11-01"},"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."]}