{"id":"CVE-2026-91132","title":"Discourse is an open-source discussion platform","summary":"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 …","severity":"medium","cvss":4.3,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N","cwe":["CWE-346"],"vendor":"discourse","product":"discourse","affected":["discourse < 2026.8.0","discourse >= 2026.7.0-latest, < 2026.7.2","discourse >= 2026.6.0-latest, < 2026.6.3","discourse >= 2026.1.0-latest, < 2026.1.8"],"published":"2026-09-24","updated":"2026-09-24","sourceUpdated":"2026-09-24T17:17:08.853","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-91132","references":[{"url":"https://github.com/discourse/discourse/commit/80968704c1acb1d2ea2c6011dbf6c02ff13238e5","label":"security-advisories@github.com"},{"url":"https://github.com/discourse/discourse/commit/d5ae0940707f95da5bc4562f7b544243e3103f8a","label":"security-advisories@github.com"},{"url":"https://github.com/discourse/discourse/commit/d88e02ceb2eede4d8b851d9fe8aef753f3aa40b9","label":"security-advisories@github.com"},{"url":"https://github.com/discourse/discourse/commit/db8064f2a2a2a3feb3308a1c932ac61d950c9e56","label":"security-advisories@github.com"},{"url":"https://github.com/discourse/discourse/pull/42882","label":"security-advisories@github.com"},{"url":"https://github.com/discourse/discourse/security/advisories/GHSA-4q3q-hph3-3rvp","label":"security-advisories@github.com"}],"tags":["nvd","cve.org"],"ingestedAt":"2026-09-24T17:48:30.387Z","slug":"CVE-2026-91132","body":"## Overview\n\nDiscourse 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.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":24,"depthScoreParts":{"impact":23.7,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}