{"id":"CVE-2017-20290","title":"Discourse < 1.9.0.beta13 Reflected XSS via /email/unsubscribed","summary":"Discourse 1.9.0.beta2 before 1.9.0.beta13 contains a reflected cross-site scripting vulnerability that allows unauthenticated attackers to inject scripts through the email parameter of /email/unsubscribed. Attackers can craft GET request…","severity":"medium","cvss":6.1,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N","cvssSource":"cna","cwe":["CWE-79"],"vendor":"Discourse","product":"Discourse","affected":["Discourse >= 1.9.0.beta2 < 1.9.0.beta13"],"published":"2026-10-22","updated":"2026-10-22","sourceUpdated":"2026-10-22T10:57:24.711Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2017-20290","references":[{"url":"https://github.com/discourse/discourse/commit/a6f2533d38","label":"Fix Commit"},{"url":"https://github.com/discourse/discourse/commit/6e37f09b19","label":"Introducing Commit"},{"url":"https://github.com/projectdiscovery/nuclei-templates/blob/main/http/vulnerabilities/other/discourse-xss.yaml","label":"Nuclei Template"},{"url":"https://www.vulncheck.com/advisories/discourse-1.9.0-beta13-reflected-xss-via-email-unsubscribed","label":"VulnCheck Advisory: Discourse < 1.9.0.beta13 Reflected XSS via /email/unsubscribed"}],"tags":["cve.org"],"ingestedAt":"2026-10-22T11:37:02.345Z","slug":"CVE-2017-20290","body":"## Overview\n\nDiscourse 1.9.0.beta2 before 1.9.0.beta13 contains a reflected cross-site scripting vulnerability that allows unauthenticated attackers to inject scripts through the email parameter of /email/unsubscribed. Attackers can craft GET requests with SVG onload payloads, which unsubscribed.html.erb renders unescaped via html_safe, executing JavaScript in victims' browsers. Exploitation evidence was first observed by the Shadowserver Foundation on 2023-10-19.\n\n## Affected\n\n- `Discourse >= 1.9.0.beta2 < 1.9.0.beta13`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":34,"depthScoreParts":{"impact":33.6,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}