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

Read the record on cve.org

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

CVSSScoreVectorSource
3.10.0 NoneCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:NGitHub_M

Weaknesses

  • CWE-116 Improper Encoding or Escaping of Output

Affected Products

ProductVersions
PrivateBinPrivateBin
  • < 2.0.5Affected

References

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