{"id":"CVE-2026-103974","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.","aliases":["GHSA-43g7-r6hp-ccf8"],"modified":"2026-10-16T02:47:29.917033232Z","published":"2026-10-14T18:17:13.770Z","database_specific":{"cna_assigner":"GitHub_M","cwe_ids":["CWE-79"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/103xxx/CVE-2026-103974.json"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/103xxx/CVE-2026-103974.json"},{"type":"ADVISORY","url":"https://github.com/lichess-org/lila/security/advisories/GHSA-43g7-r6hp-ccf8"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-103974"},{"type":"FIX","url":"https://github.com/lichess-org/lila/commit/c54596c9e1569d378fe20f80d4c790c6fdee54c4"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/lichess-org/lila","events":[{"introduced":"0"},{"fixed":"c54596c9e1569d378fe20f80d4c790c6fdee54c4"}],"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-2026-103974.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N"}]}