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Postiz Skool integration JWT forgery leading to cross-tenant SUPERADMIN takeover

IdentifiersCVE-2026-48781CWE-345

CVE-2026-48781 is a critical authentication/authorization flaw in Postiz, an AI social media scheduling tool, affecting versions prior to 2.21.8. In the Skool integration callback, attacker-controlled JSON was signed into a session-shaped JWT using the application's JWT_SECRET. Postiz's authentication middleware then trusted the claims in that JWT without re-resolving the user from the database or otherwise independently validating the asserted identity and privilege level. As a result, an authenticated attacker could forge a JWT containing arbitrary claims, including elevated role and tenant context, and obtain a forged SUPERADMIN session. The flaw enables cross-tenant impersonation of arbitrary organizations and effectively breaks trust boundaries between tenants on the same Postiz instance.

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ANALYST BRIEF

Impact, mitigation & remediation

What it means. What to do now. Patch path, mitigations, and the assume-compromise checklist.

Impact

What an attacker gets, and what they’ve been doing with it.

Successful exploitation allows full compromise of the affected Postiz instance from the perspective of application authorization. An attacker can obtain SUPERADMIN-level access, impersonate arbitrary organizations, access all parts of Postiz on the targeted instance, view data associated with users registered to that instance, and post content in the name of victims through social media channels connected to the compromised Postiz deployment. The issue has high confidentiality, integrity, and availability impact because it enables unauthorized access to tenant data, unauthorized administrative actions, and abuse of integrated publishing capabilities.

Mitigation

If you can’t patch tonight, do this now.

If immediate upgrade is not possible, disable or restrict the vulnerable Skool integration callback path where feasible, and monitor for anomalous session creation, privilege escalation, organization impersonation, and unauthorized posting activity. Review logs for signs of forged SUPERADMIN sessions or cross-tenant access. Rotate JWT secrets and force re-authentication to reduce the usefulness of previously forged or issued tokens. As a defense-in-depth measure, validate JWT claims against server-side state and avoid deriving trusted session state directly from attacker-influenced callback payloads.

Remediation

Patch, then assume compromise.

Upgrade Postiz to version 2.21.8 or later, where the issue is fixed. Ensure authentication middleware does not trust privilege- or identity-bearing JWT claims from integration callbacks without authoritative server-side validation. Re-resolve the user and authorization context from the database before establishing a session, and restrict callback processing so attacker-controlled data cannot be transformed directly into trusted session tokens. If there is any possibility the JWT secret was exposed or abused, rotate JWT_SECRET and invalidate existing sessions/tokens as part of incident response.
PUBLIC EXPLOITS

Exploits

No public exploits tracked yet. Mallory keeps watching.

VALID 0 / 0 TOTALView more in app

No public exploit code observed for this vulnerability.

ACTIVITY FEED

Recent activity

2 sources tracked across advisories, community write-ups, and news. New activity surfaces here as Mallory finds it.

2 SOURCESView more in app
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Exposure mapping

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Threat actor evidence

Every observed campaign linking this CVE to a named adversary.

Associated malware

Malware families riding this exploit, with evidence and IOCs.

Detection signatures

YARA, Sigma, Snort, and vendor rules, auto-deployed to your SIEM.

Vendor-by-vendor mapping

Cross-references every affected SKU, including bundled OEM variants.

Social activity1

Community discussion across Reddit, Mastodon, and other social sources.

EXTERNAL REFERENCES
MITRE CVE
cve.org · CVE-2026-48781
NVD
nvd.nist.gov/vuln/detail/CVE-2026-48781
MITRE CWE · CWE-345
cwe.mitre.org