Vulnerability · Published Jun 16, 2026 · Assigned by GitHub_M

CVE-2026-48781Postiz has cross-tenant SUPERADMIN takeover via Skool-provider JWT forgery

Critical 9.9

In plain English

A critical-severity insufficient verification of data authenticity 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 0.2% (higher than 11% of all known vulnerabilities).

Severity (CVSS 3.1)9.9Critical

Exploit odds (30 days)0.2%top 88.8% 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. In versions prior to 2.21.8, the Skool integration callback signed an attacker-controlled JSON blob into a session-shape JWT using the application's JWT_SECRET, and the auth middleware trusted every claim in that JWT without re-resolving the user from the database. Any authenticated Postiz user could forge a SUPERADMIN session and impersonate arbitrary organizations. This allowed Full Access to the following: all parts of Postiz, including users registered to the specific instance and the ability to post in the name of the victim's social media channels added to that Postiz instance. This issue has been fixed in version 2.21.8.

Affected products (as reported)

Vendor	Product	Versions
gitroomhq	postiz-app	< 2.21.8

Weakness: CWE-302, CWE-345, CWE-863 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

References

https://github.com/gitroomhq/postiz-app/security/advisories/GHSA-j77w-h625-56q2 x_refsource_CONFIRM
https://github.com/gitroomhq/postiz-app/commit/23696d2973510ae1f3f48bfa41a6bfbbf9827b05 x_refsource_MISC
https://gadvisory.org/advisories/PSA-2026-2CAQ96 x_refsource_MISC
http://github.com/gitroomhq/postiz-app/releases/tag/v2.21.8 x_refsource_MISC