CVE-2026-35208

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.

CVSS

No CVSS.

References

Link	Resource
https://github.com/lichess-org/lila/commit/0d5002696ae705e1888bf77de107c73de57bb1b3
https://github.com/lichess-org/lila/security/advisories/GHSA-v7gh-939r-pfjq
https://vimeo.com/1175908262

Configurations

No configuration.

History

06 Apr 2026, 21:16

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-04-06 21:16

Updated : 2026-04-07 13:20

NVD link : CVE-2026-35208

Mitre link : CVE-2026-35208

CVE.ORG link : CVE-2026-35208

JSON object : View

Products Affected

No product.

CWE

CWE-79

Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

CWE-116

Improper Encoding or Escaping of Output

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