CVE-2026-55891CWE-116

CVE-2026-55891

published August 29, 2026

CVSS v3.1
0.0
EPSS
1%
Percentile
44.6
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
0.0 · NONE
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:N
CVSS v4.0
Not supplied
EPSS
0.00539 · 44.6th percentile
Weakness
CWE-116 · Improper Encoding or Escaping of Output
Published
2026-08-29T02:16Z
References (4)
EPSS history
Timeline
  • 30 AUG 16:18Z
    EPSS moved — → 0%
    epss
  • 28 AUG 20:23Z
    PrivateBin: Reflected JSON injection in backend responses via unescaped REQUEST_URI
    cvelistv5