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

Quick assessment

Affected
PrivateBin PrivateBin
Exploitation
No confirmed in-the-wild exploitation; assess based on exposure
Recommended action
Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.

PrivateBin 是一个在线代码/文本粘贴（pastebin）服务，服务器端对粘贴的数据采用“零知识”（zero-knowledge）设计。在 2.0.5 版本之前， 中的 方法会对 应用 过滤器，但该过滤器并不会移除引号、尖括号或撇号（apostrophes）。随后， 会将这个由攻击者控制且未完全净化的值存储到 中。 接着， 中的 方法使用 将该值直接插入到 JSON-LD 模板（如 、 以及 和 使用的其他 JSON-LD 模板）中，且插入时没有进行 JSON 转义。 如果一个 HTTP 客户端、代理或结构

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I. Basic Information for CVE-2026-55891

Vulnerability Information
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Vulnerability Title
PrivateBin: Reflected JSON injection in backend responses via unescaped REQUEST_URI
Source: CVE Program / CVE List V5
Vulnerability 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.
Source: CVE Program / CVE List V5
CVSS Information
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:N
Source: CVE Program / CVE List V5
Vulnerability Type
对输出编码和转义不恰当
Source: CVE Program / CVE List V5

Affected Products

Vendor Product Affected Versions CPE Subscribe
PrivateBin PrivateBin < 2.0.5 -

II. Public POCs for CVE-2026-55891

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III. Intelligence Information for CVE-2026-55891

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Patches & Fixes for CVE-2026-55891 (2)

Vendor Advisories for CVE-2026-55891 (1)

IV. Related Vulnerabilities

Same product: PrivateBin
Same vendor: PrivateBin
Same weakness: CWE-116

V. Comments for CVE-2026-55891

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