CVE-2026-63135
YOURLS: Stored XSS in referrer statistics chart via crafted Referer header
- Published
- Updated
- Reserved
- Assigned by
- GitHub_M
Description
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.
Public exploit
A reference of the record is tagged as an exploit or proof of concept: anyone can try it against an unpatched system. CISA's SSVC rates its exploitation: a proof of concept is public.
- https://github.com/YOURLS/YOURLS/security/advisories/GHSA-5h77-88j3-r659 (opens in a new tab)x_refsource_CONFIRMexploit
Timeline
ID reserved
By GitHub_M
- 37 days later
· 37 days later
Published
- 5 days later
· 5 days later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| GitHub_MCNA (assigner) | 3.1 | High8.2 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:H/A:N |
| NVDNVD · Deferred | 3.1 | High8.2 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:H/A:N |
- EPSS (exploitation in 30 days)
- 0.43% · top 63% of all CVEs (7 Nov 2026)
- CISA SSVC
- Exploitation: poc · Automatable: no · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 8.2.
Weakness
Affected products
Affected packages
From reviewed advisories of the GitHub Advisory Database.
- Packagistyourls/yourlsGHSA-5h77-88j3-r659 (opens in a new tab)
References (4)
- https://github.com/YOURLS/YOURLS/security/advisories/GHSA-5h77-88j3-r659 (opens in a new tab)x_refsource_CONFIRMexploit
- https://github.com/YOURLS/YOURLS/pull/4107 (opens in a new tab)x_refsource_MISC
- https://github.com/YOURLS/YOURLS/commit/e1e93476655107e6caab34e52259eb1c91079ec7 (opens in a new tab)x_refsource_MISC
- https://github.com/YOURLS/YOURLS/releases/tag/1.10.4 (opens in a new tab)x_refsource_MISC
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisory GHSA-5h77-88j3-r659 (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2026-63135)Record last updated .