CVE-2026-42556

CriticalCVSS 9.0/10Last modified Jul 24, 2026

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.

Metrics

CVSS 3.1 9.0/10CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H

Weakness enumeration

CWE-79

Affected software

Vendor	Product	Versions
gitroomhq	postiz-app	>= 2.21.6, < 2.21.7

References

https://github.com/gitroomhq/postiz-app/releases/tag/v2.21.7Product, Release Notes
https://github.com/gitroomhq/postiz-app/security/advisories/GHSA-hhxq-3wg7-4rj8Vendor Advisory

Timeline

Published: May 8, 2026
Last modified: Jul 24, 2026
NVD status: Analyzed

Related CVEs from 2026

CVE-2026-425579.6jupyterlab is an extensible environment for interactive and reproducible computing, based on the Jupyter Notebook Architecture. Prior to 4.5 CVE-2026-425587.6Xibo is an open source digital signage platform with a web content management system and Windows display player software. Prior to 4.4.2, a CVE-2026-425598.8RMCP is an official Rust SDK for the Model Context Protocol. Prior to version 1.4.0, the rmcp crate's Streamable HTTP server transport (crat CVE-2026-42568.2Improper neutralization of special elements used in an LDAP query ('LDAP injection') vulnerability in PEAKUP Technology Inc. PassGate allows CVE-2026-425609.1auth provides authentication via oauth2, direct and email. From versions 1.18.0 to before 1.25.2 and 2.0.0 to before 2.1.2, the Patreon OAut CVE-2026-425617.5Python-Multipart is a streaming multipart parser for Python. Prior to 0.0.27, python-multipart has a denial of service vulnerability in mult CVE-2026-425628.3Plainpad is a self hosted note taking app. Prior to version 1.1.1, Plainpad allows a low-privilege authenticated user to self-escalate to ad CVE-2026-425637.7Dulwich is a pure-Python implementation of the Git file formats and protocols. Starting in version 0.24.0 and prior to version 1.2.5, Dulwic CVE-2026-425648.2jotty·page is a self-hosted app for your checklists and notes. Prior to 1.22.0, an unauthenticated path traversal vulnerability exists in /a CVE-2026-425654.3@workos/authkit-session is a toolkit for building WorkOS AuthKit framework integrations. Prior to 0.5.1, an open redirect vulnerability exis CVE-2026-425667.5Meshtastic is an open source mesh networking solution. Prior to version 2.7.23.b246bcd, a single node advertising a User.long_name that cont CVE-2026-425677.5Svelte is a performance oriented web framework. From version 5.51.5 to before version 5.55.7, an internal regex in the Svelte runtime can ta