CVE-2026-55891
PrivateBin: Reflected JSON injection in backend responses via unescaped REQUEST_URI
- State
- Published
- Severity
- 0.0 None
- Published
- Aug 28, 2026
- Updated
- Aug 31, 2026
- Reserved
- Jun 17, 2026
Description
PrivateBin is an online pastebin where the server has zero knowledge of pasted data. Prior to 2.0.5, Request::getRequestUri() in lib/Request.php passes $_SERVER['REQUEST_URI'] through FILTER_SANITIZE_URL, which does not remove quotation marks, angle brackets, or apostrophes, and Controller::_init() stores the attacker-controlled value in Controller::$_urlBase. Controller::_jsonld() in lib/Controller.php then uses str_replace() to insert that value without JSON escaping into js/types.jsonld, js/paste.jsonld, and the other JSON-LD templates used by /?jsonld= and /?pasteid. A raw quotation mark delivered by an HTTP client, proxy, or structured-data crawler that does not normalize the request target can break out of the JSON string and inject arbitrary key-value data into a CORS-open application/ld+json response. The jsonld branch in Controller::__construct() returns before _setCacheHeaders(), so the response also lacks X-Content-Type-Options: nosniff, Content Security Policy, X-Frame-Options, and Referrer-Policy. Direct script execution was not demonstrated, but manipulated responses can affect structured-data consumers or combine with less strict clients. This issue is fixed in version 2.0.5.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 3.1 | 0.0 None | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:N | GitHub_M |
Weaknesses
- CWE-116 Improper Encoding or Escaping of Output
Affected Products
| Product | Versions |
|---|---|
PrivateBinPrivateBin |
|
References
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