{"schema":"threatline.record/2","record":{"id":"CVE-2026-103974","aliases":["GHSA-43g7-r6hp-ccf8"],"summary":"lichess.org: Stored HTML Injection via PGN Annotator Tag in Studies","details":"lichess.org is the forever free, adless and open source chess server. Prior to commit c54596c9e1569d378fe20f80d4c790c6fdee54c4, a user who can add a chapter to a study can place attacker-controlled text in the PGN Annotator tag, which becomes Comment.Author.External and is returned verbatim by authorText. When a study node has at least two comments, ui/analyse/src/treeView/inlineView.ts interpolates that author string into HTML passed to the innerHTML hook without escaping it. Opening the affected study can therefore render stored attacker-controlled HTML and CSS for other viewers, including navigation to an attacker-controlled site, content spoofing, and CSS-based data exposure, although the site's content security policy blocks injected JavaScript. This vulnerability is fixed by commit c54596c9e1569d378fe20f80d4c790c6fdee54c4.","categories":["Unclassified"],"product":"lila","vendor":"lichess-org","ecosystem":null,"affected_ranges":[{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-103974","source_modified_at":"2026-10-14T19:41:15.577Z","fetched_at":"2026-10-23T18:48:36.087640Z","product":"lila","vendor":"lichess-org","versions":[{"status":"affected","version":"< c54596c9e1569d378fe20f80d4c790c6fdee54c4"}],"defaultStatus":null},{"source":"GitHub Advisory Database","source_url":"https://github.com/lichess-org/lila/security/advisories/GHSA-43g7-r6hp-ccf8","source_modified_at":"2026-10-01T18:07:31Z","fetched_at":"2026-10-23T21:47:51.402276Z","package":{"name":"lila","ecosystem":null},"range":"b2c355cd45f823e31e92aa56ca2ca162e979909a"}],"fixed_versions":[],"cvss":5.4,"severity":"Medium","kev":{"listed":false},"epss":{"probability":0.00214,"percentile":0.11219,"score_date":"2026-10-23"},"published_at":"2026-10-14T18:17:13.770Z","modified_at":"2026-10-14T19:41:15.577Z","provenance":[{"source":"CVE List","url":"https://www.cve.org/CVERecord?id=CVE-2026-103974","fetched_at":"2026-10-23T18:48:36.087640Z","source_modified_at":"2026-10-14T19:41:15.577Z"},{"source":"GitHub Advisory Database","url":"https://github.com/lichess-org/lila/security/advisories/GHSA-43g7-r6hp-ccf8","fetched_at":"2026-10-23T21:47:51.402276Z","source_modified_at":"2026-10-01T18:07:31Z"},{"source":"EPSS","url":"https://api.first.org/data/v1/epss?cve=CVE-2026-103974","fetched_at":"2026-10-23T18:42:43.628194Z","source_modified_at":"2026-10-23"}],"sources":["CVE List","GitHub Advisory Database","EPSS"],"references":[{"source":"CVE List","url":"https://github.com/lichess-org/lila/security/advisories/GHSA-43g7-r6hp-ccf8","tags":["exploit"]},{"source":"CVE List","url":"https://github.com/lichess-org/lila/commit/c54596c9e1569d378fe20f80d4c790c6fdee54c4","tags":["x_refsource_MISC"]}],"locations":[],"motoko_assessment":{"status":"requires_architecture_review","automatic_remediation":false},"cve_state":"PUBLISHED","cvss_source":"CVE List","ssvc":{"exploitation":"poc","automatable":"no","technical_impact":"partial","assessed_at":"2026-10-14T19:40:54.734332Z"},"classification":{"method":"product-first software-layer rules","rules_version":"2.1","matched_on":null,"confidence":"unknown","reviewed":false},"change_timestamp":"2026-10-14T19:41:15.577Z","content_hash":"47567cc4f37fe2d1842808ffb6a7dd4598efd21fc0e848c7b187b7b584c6f98a"}}