{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "extracted_events": [
              {
                "introduced": "2.21.6"
              },
              {
                "fixed": "2.21.7"
              }
            ],
            "source": "AFFECTED_FIELD"
          },
          "events": [
            {
              "introduced": "3ea302202dc0daa3db577eb7c68374cdc1ddbc3c"
            },
            {
              "fixed": "7236213ea4520bd67b45688c2787d1f4586b3b51"
            }
          ],
          "repo": "https://github.com/gitroomhq/postiz-app",
          "type": "GIT"
        }
      ],
      "versions": [
        "2.21.6"
      ]
    }
  ],
  "aliases": [
    "GHSA-hhxq-3wg7-4rj8"
  ],
  "database_specific": {
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
      "CWE-79"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/42xxx/CVE-2026-42556.json"
  },
  "details": "Postiz is an AI social media scheduling tool. From version 2.21.6 to before version 2.21.7, any authenticated user who can create a post can store arbitrary HTML in post content by tampering their own save request and send the public preview link /p/\u003cpostId\u003e?share=true to another user. The preview page renders that stored HTML with dangerouslySetInnerHTML on the main application origin. This issue has been patched in version 2.21.7.",
  "id": "CVE-2026-42556",
  "modified": "2026-07-27T03:56:33.235863700Z",
  "published": "2026-05-08T22:28:33.086Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/gitroomhq/postiz-app/releases/tag/v2.21.7"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/42xxx/CVE-2026-42556.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/gitroomhq/postiz-app/security/advisories/GHSA-hhxq-3wg7-4rj8"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-42556"
    }
  ],
  "schema_version": "1.8.0",
  "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 stored XSS in public preview page"
}