{"id":"CVE-2026-27570","summary":"Discourse Vulnerable to Stored XSS via Shared AI Conversation Onebox","details":"Discourse is an open-source discussion platform. Prior to versions 2026.3.0-latest.1, 2026.2.1, and 2026.1.2, the onebox method in the SharedAiConversation model renders the conversation title directly into HTML without proper sanitization. Versions 2026.3.0-latest.1, 2026.2.1, and 2026.1.2 contain a patch. As a workaround, tighten access by changing the `ai_bot_public_sharing_allowed_groups` site setting.","aliases":["BIT-discourse-2026-27570","GHSA-hfxw-89hw-vwmv"],"modified":"2026-08-12T03:51:35.787947274Z","published":"2026-03-19T20:52:17.572Z","database_specific":{"cna_assigner":"GitHub_M","cwe_ids":["CWE-79"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/27xxx/CVE-2026-27570.json"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/27xxx/CVE-2026-27570.json"},{"type":"ADVISORY","url":"https://github.com/discourse/discourse/security/advisories/GHSA-hfxw-89hw-vwmv"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-27570"},{"type":"FIX","url":"https://github.com/discourse/discourse/commit/43a5a60b595f0120e6adfc131f2408508fe341f1"},{"type":"FIX","url":"https://github.com/discourse/discourse/commit/c14f8f52b7999328bd9f8665f2ecfa24dadc4bf1"},{"type":"FIX","url":"https://github.com/discourse/discourse/commit/f2aafa5c7467c94fcd4ebd36785a98e77ca088cc"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/discourse/discourse","events":[{"introduced":"322d3c0ac6a8f133b3f82875e9dbbe310f638c1b"},{"fixed":"808b2ac23d8ff421563b40203091026732471c60"},{"introduced":"f7cec86997edc21d6074ceb7666f7e2e6e1b1fdf"},{"fixed":"f38464e46df1b8c51f7d60826502476908d6bb2b"},{"introduced":"896e810e1b296478bba91559a8fc89a9926f11fe"},{"fixed":"43a5a60b595f0120e6adfc131f2408508fe341f1"},{"fixed":"c14f8f52b7999328bd9f8665f2ecfa24dadc4bf1"},{"fixed":"f2aafa5c7467c94fcd4ebd36785a98e77ca088cc"}],"database_specific":{"source":["CPE_RANGE","CPE_STRING","REFERENCES"],"cpe":["cpe:2.3:a:discourse:discourse:*:*:*:*:*:*:*:*","cpe:2.3:a:discourse:discourse:2026.3.0:*:*:*:latest:*:*:*"],"extracted_events":[{"introduced":"2026.1.0"},{"fixed":"2026.1.2"},{"introduced":"2026.2.0"},{"fixed":"2026.2.1"},{"introduced":"2026.3.0"},{"last_affected":"2026.3.0"}]}}],"versions":["2026.3.0","= 2026.3.0-latest","v2026.1.1","v2026.2.0","v2026.3.0-latest","v2026.1.0","stable","esr","v2026.2.0-latest","v2026.1.0-latest"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-27570.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N"}]}