{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "cpe": "cpe:2.3:a:gitroom:postiz:*:*:*:*:*:*:*:*",
            "extracted_events": [
              {
                "introduced": "0"
              },
              {
                "fixed": "2.21.6"
              }
            ],
            "source": [
              "AFFECTED_FIELD",
              "CPE_RANGE",
              "REFERENCES"
            ]
          },
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "3ea302202dc0daa3db577eb7c68374cdc1ddbc3c"
            }
          ],
          "repo": "https://github.com/gitroomhq/postiz-app",
          "type": "GIT"
        }
      ]
    }
  ],
  "aliases": [
    "GHSA-44wg-r34q-hvfx"
  ],
  "database_specific": {
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
      "CWE-345",
      "CWE-434",
      "CWE-79"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/40xxx/CVE-2026-40487.json"
  },
  "details": "Postiz is an AI social media scheduling tool. Prior to version 2.21.6, a file upload validation bypass allows any authenticated user to upload arbitrary HTML, SVG, or other executable file types to the server by spoofing the `Content-Type` header. The uploaded files are then served by nginx with a Content-Type derived from their original extension (`text/html`, `image/svg+xml`), enabling Stored Cross-Site Scripting (XSS) in the context of the application's origin. This can lead to session riding, account takeover, and full compromise of other users' accounts. Version 2.21.6 contains a fix.",
  "id": "CVE-2026-40487",
  "modified": "2026-08-12T03:51:11.591272326Z",
  "published": "2026-04-18T01:19:06.588Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/gitroomhq/postiz-app/releases/tag/v2.21.6"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/40xxx/CVE-2026-40487.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/gitroomhq/postiz-app/security/advisories/GHSA-44wg-r34q-hvfx"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-40487"
    }
  ],
  "schema_version": "1.9.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:L",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Postiz Has Unrestricted File Upload via MIME Type Spoofing that Leads to Stored XSS"
}