CVE-2026-55891PrivateBin: Reflected JSON injection in backend responses via unescaped REQUEST_URI

Official 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.

Affected packages & fixed versions

Affected products (as reported)

References

• https://github.com/PrivateBin/PrivateBin/security/advisories/GHSA-xrjc-c68j-hp7w x_refsource_CONFIRM
• https://github.com/PrivateBin/PrivateBin/commit/164c839c39688533ef0086575878e8392cd21249 x_refsource_MISC
• https://github.com/PrivateBin/PrivateBin/releases/tag/2.0.5 x_refsource_MISC