All vulnerabilities
CVE-2026-103974GHSA-43g7-r6hp-ccf8

lila: lichess.org: Stored HTML Injection via PGN Annotator Tag in Studies

lichess-org lila
Open in ThreatlineRecord JSON
CVSS
5.4Medium
ExploitationPublic exploit codeCISA's assessment says proof of concept code is public, assessed 14 Oct 2026. Not in the KEV catalogCISA via CVE List
Exploit odds (EPSS)0.21%Chance of exploitation activity in the next 30 days, higher than 11% of CVEs. Scored 23 Oct 2026FIRST EPSS
Fixed inNone listedNo source names a fixed version. Check the vendor advisory below
Published14 Oct 2026Updated 14 Oct 2026CVE List

What fixes it

No source in this snapshot names a fixed version. The vendor advisories under References are the place to check.

Description

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.

Text from CVE List

Affected versions 2

  • lilaaffected: < c54596c9e1569d378fe20f80d4c790c6fdee54c4CVE List
  • lilab2c355cd45f823e31e92aa56ca2ca162e979909aGitHub

References 2