CVE-2026-63135
YOURLS is a self-hosted, customizable URL shortener written in PHP. From 1.5.1 until 1.10.4, YOURLS stores the HTTP Referer header through yourls_get_referrer(), yourls_sanitize_url_safe(), and yourls_log_redirect(), then aggregates the value in yourls-infos.php and passes the derived domain through yourls_get_domain(), yourls_stats_pie(), and yourls_google_array_to_data_table(). The chart builder concatenates labels into inline JavaScript without JavaScript-string escaping, so an unauthenticated attacker can poison the statistics of an existing short URL with a crafted referrer. When an administrator or public stats-page viewer opens the affected statistics page, attacker-controlled JavaScript executes in the YOURLS origin and can access admin-visible data, the API signature token, and privileged same-origin actions. This issue is fixed in version 1.10.4.
- CVSS 3.1
- 8.2
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:H/A:N - EPSS
- 0.4% chance of exploitation in the next 30 days; higher than 36% of CVEs (scores of 2026-10-25)
- CWE
- CWE-79
- Published
- Modified
- Record from
- the NVD, synced
References
- https://github.com/YOURLS/YOURLS/commit/e1e93476655107e6caab34e52259eb1c91079ec7
- https://github.com/YOURLS/YOURLS/pull/4107
- https://github.com/YOURLS/YOURLS/releases/tag/1.10.4
- https://github.com/YOURLS/YOURLS/security/advisories/GHSA-5h77-88j3-r659
- https://github.com/YOURLS/YOURLS/security/advisories/GHSA-5h77-88j3-r659