CVE-2026-48781: Postiz has cross-tenant SUPERADMIN takeover via Skool-provider JWT forgery
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 JWTSECRET, 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 Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
Postizto a version that resolves this vulnerability.Fixed in 2.21.8
Event History
Frequently Asked Questions
What is the severity of CVE-2026-48781?
The severity of CVE-2026-48781 is critical with a score of 9.9.
How do I fix CVE-2026-48781?
To fix CVE-2026-48781, update Postiz to version 2.21.8 or later.
What type of vulnerability is CVE-2026-48781?
CVE-2026-48781 is a cross-tenant SUPERADMIN takeover vulnerability via Skool-provider JWT forgery.
What impact does CVE-2026-48781 have?
CVE-2026-48781 can lead to unauthorized access and control over the Postiz application by exploiting JWT forgery.
Who is affected by CVE-2026-48781?
CVE-2026-48781 affects all users of Postiz versions prior to 2.21.8.