PrivateBin: Reflected JSON injection in backend responses via unescaped REQUEST_URI

{
  "id": "fd0db4fd9b0b25fd7c8caffe97dbbae168d2ed4e97909ea0dcac2dbc1eb46263",
  "url": "https://osv.dev/vulnerability/CVE-2026-55891",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "PrivateBin: Reflected JSON injection in backend responses via unescaped REQUEST_URI",
    "summary": "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.",
    "evidence": "osv:CVE-2026-55891",
    "products": [],
    "severity": "unknown",
    "structured": {
      "id": "CVE-2026-55891",
      "aliases": [
        "CVE-2026-55891",
        "GHSA-xrjc-c68j-hp7w"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/privatebin/privatebin",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "3035d6e5d3cceb7f06f7b7bb80968727879c52b0"
                },
                {
                  "fixed": "164c839c39688533ef0086575878e8392cd21249"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "2.0.5"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StringRangeExpression"
                  },
                  {
                    "range": [
                      {
                        "fixed": "164c839c39688533ef0086575878e8392cd21249"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  },
                  {
                    "range": [
                      {
                        "fixed": "3035d6e5d3cceb7f06f7b7bb80968727879c52b0"
                      }
                    ],
                    "source": "REFERENCES_TAG",
                    "original_tag": "2.0.5"
                  }
                ]
              }
            }
          ],
          "versions": [
            "2.0.4",
            "1.7.8",
            "2.0.3",
            "2.0.2",
            "2.0.1",
            "2.0.0",
            "1.7.7",
            "1.7.6",
            "1.7.5",
            "1.7.3",
            "1.7.2",
            "1.7.1",
            "1.7.0",
            "1.6.2",
            "1.6.1",
            "1.6.0",
            "1.5.2",
            "1.5.1",
            "1.5.0",
            "1.4.0",
            "1.3.5",
            "1.3.4",
            "1.3.3",
            "1.3.2",
            "1.2.1",
            "1.3.1",
            "1.3",
            "1.1",
            "1.0",
            "0.22",
            "0.21.1",
            "0.21",
            "0.20",
            "0.19",
            "0.18"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-55891.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:38.346265473Z",
      "provider": "osv",
      "references": [
        "https://github.com/PrivateBin/PrivateBin/releases/tag/2.0.5",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/55xxx/CVE-2026-55891.json",
        "https://github.com/PrivateBin/PrivateBin/security/advisories/GHSA-xrjc-c68j-hp7w",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-55891",
        "https://github.com/PrivateBin/PrivateBin/commit/164c839c39688533ef0086575878e8392cd21249"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-116"
        ],
        "cna_assigner": "GitHub_M",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/55xxx/CVE-2026-55891.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-55891",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": null
  },
  "source_id": "core-osv",
  "document_id": 505730,
  "published_at": "2026-08-28T20:23:50.477+00:00"
}