Vulnerability · Published May 8, 2026 · Assigned by GitHub_M

CVE-2026-42556Postiz stored XSS in public preview page

High 8.9

In plain English

A high-severity cross-site scripting in postiz-app from gitroomhq. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 18% of all known vulnerabilities).

Severity (CVSS 3.1)8.9High

Exploit odds (30 days)0.3%top 82.5% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official 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.

Affected products (as reported)

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

Weakness: CWE-79 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:L

References

https://github.com/gitroomhq/postiz-app/security/advisories/GHSA-hhxq-3wg7-4rj8 x_refsource_CONFIRM
https://github.com/gitroomhq/postiz-app/releases/tag/v2.21.7 x_refsource_MISC