Postiz stored XSS in public preview page_CVE-2026-42556

8.9 / 10

HIGH

CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:L

Description

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/<postId>?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.

Basic Information

ID CVE-2026-42556

Source GitHub_M

Published May 8, 2026 at 22:28

Affected Product

Vendor gitroomhq

Product postiz-app

Version >= 2.21.6, < 2.21.7

Affected Versions gitroomhq postiz-app >= 2.21.6, < 2.21.7

CWE Classification

CWE-79

References

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    "published": "2026-05-08T22:28:33.086Z",
    "modified": "2026-05-08T22:28:33.086Z",
    "type": "cve",
    "title": "Postiz stored XSS in public preview page",
    "source": "GitHub_M",
    "references": "https://github.com/gitroomhq/postiz-app/security/advisories/GHSA-hhxq-3wg7-4rj8\nhttps://github.com/gitroomhq/postiz-app/releases/tag/v2.21.7",
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    "sourceData": "gitroomhq postiz-app >= 2.21.6, < 2.21.7",
    "sourceHref": "",
    "cvss": {
        "score": 8.9,
        "severity": "HIGH",
        "vector": "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:L",
        "version": "3.1"
    },
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        "cvssV3": {
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