{"id":"CVE-2026-35208","summary":"lichess.org has an Unsanitized Stream Title Injection on /streamer","details":"lichess.org is the forever free, adless and open source chess server. Any approved streamer can inject arbitrary HTML into /streamer and the homepage “Live streams” widget by placing markup in their Twitch/YouTube stream title. CSP is present and blocks inline script execution, but the issue is still a server-side HTML injection sink. To trigger this, a Lichess account only needs to satisfy the normal streamer requirements and get approved. Per Streamer.canApply, that means an account older than 2 days with at least 15 games, or a verified/titled account. After moderator approval, once the streamer goes live, Lichess pulls the platform title and renders it into the UI as-is. No extra privileges are needed beyond a normal approved streamer profile. This vulnerability is fixed with commit 0d5002696ae705e1888bf77de107c73de57bb1b3.","aliases":["GHSA-v7gh-939r-pfjq"],"modified":"2026-07-08T07:34:21.720121345Z","published":"2026-04-06T20:06:25.821Z","database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/35xxx/CVE-2026-35208.json","unresolved_ranges":[{"extracted_events":[{"fixed":"0d5002696ae705e1888bf77de107c73de57bb1b3"}],"source":"AFFECTED_FIELD"}],"cna_assigner":"GitHub_M","cwe_ids":["CWE-116","CWE-79"]},"references":[{"type":"WEB","url":"https://vimeo.com/1175908262"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/35xxx/CVE-2026-35208.json"},{"type":"ADVISORY","url":"https://github.com/lichess-org/lila/security/advisories/GHSA-v7gh-939r-pfjq"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-35208"},{"type":"FIX","url":"https://github.com/lichess-org/lila/commit/0d5002696ae705e1888bf77de107c73de57bb1b3"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/lichess-org/lila","events":[{"introduced":"0"},{"fixed":"0d5002696ae705e1888bf77de107c73de57bb1b3"}],"database_specific":{"source":"REFERENCES"}}],"versions":["pre-responsive","pre-bcrypt","v1.1.0","v1.0.0"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-35208.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N"}]}