{
  "containers": {
    "cna": {
      "affected": [
        {
          "product": "postiz-app",
          "vendor": "gitroomhq",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 2.21.6"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "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\u0027s origin. This can lead to session riding, account takeover, and full compromise of other users\u0027 accounts. Version 2.21.6 contains a fix."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "LOW",
            "baseScore": 8.9,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "HIGH",
            "privilegesRequired": "LOW",
            "scope": "CHANGED",
            "userInteraction": "REQUIRED",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:L",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-79",
              "description": "CWE-79: Improper Neutralization of Input During Web Page Generation (\u0027Cross-site Scripting\u0027)",
              "lang": "en",
              "type": "CWE"
            }
          ]
        },
        {
          "descriptions": [
            {
              "cweId": "CWE-345",
              "description": "CWE-345: Insufficient Verification of Data Authenticity",
              "lang": "en",
              "type": "CWE"
            }
          ]
        },
        {
          "descriptions": [
            {
              "cweId": "CWE-434",
              "description": "CWE-434: Unrestricted Upload of File with Dangerous Type",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-04-18T01:19:06.588Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/gitroomhq/postiz-app/security/advisories/GHSA-44wg-r34q-hvfx",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/gitroomhq/postiz-app/security/advisories/GHSA-44wg-r34q-hvfx"
        },
        {
          "name": "https://github.com/gitroomhq/postiz-app/releases/tag/v2.21.6",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/gitroomhq/postiz-app/releases/tag/v2.21.6"
        }
      ],
      "source": {
        "advisory": "GHSA-44wg-r34q-hvfx",
        "discovery": "UNKNOWN"
      },
      "title": "Postiz Has Unrestricted File Upload via MIME Type Spoofing that Leads to Stored XSS"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-40487",
    "datePublished": "2026-04-18T01:19:06.588Z",
    "dateReserved": "2026-04-13T19:50:42.114Z",
    "dateUpdated": "2026-04-18T01:19:06.588Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-40487\",\"sourceIdentifier\":\"security-advisories@github.com\",\"published\":\"2026-04-18T02:16:11.670\",\"lastModified\":\"2026-04-18T02:16:11.670\",\"vulnStatus\":\"Received\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"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\u0027s origin. This can lead to session riding, account takeover, and full compromise of other users\u0027 accounts. Version 2.21.6 contains a fix.\"}],\"metrics\":{\"cvssMetricV31\":[{\"source\":\"security-advisories@github.com\",\"type\":\"Secondary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:L\",\"baseScore\":8.9,\"baseSeverity\":\"HIGH\",\"attackVector\":\"NETWORK\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"LOW\",\"userInteraction\":\"REQUIRED\",\"scope\":\"CHANGED\",\"confidentialityImpact\":\"HIGH\",\"integrityImpact\":\"HIGH\",\"availabilityImpact\":\"LOW\"},\"exploitabilityScore\":2.3,\"impactScore\":6.0}]},\"weaknesses\":[{\"source\":\"security-advisories@github.com\",\"type\":\"Primary\",\"description\":[{\"lang\":\"en\",\"value\":\"CWE-79\"},{\"lang\":\"en\",\"value\":\"CWE-345\"},{\"lang\":\"en\",\"value\":\"CWE-434\"}]}],\"references\":[{\"url\":\"https://github.com/gitroomhq/postiz-app/releases/tag/v2.21.6\",\"source\":\"security-advisories@github.com\"},{\"url\":\"https://github.com/gitroomhq/postiz-app/security/advisories/GHSA-44wg-r34q-hvfx\",\"source\":\"security-advisories@github.com\"}]}}"
  }
}