Home

Description

Postiz is an AI social media scheduling tool. Versions prior to 2.21.8 contained an unauthenticated endpoint that accepted a signed token and applied subscription-enforcement side effects to the organization referenced in that token's claims, without verifying the token's intended purpose. The endpoint, /public/modify-subscription, could not change the persisted subscription tier, but it did execute enforcement-related side effects on the caller's own organization, including adjusting team-member enablement state, disabling integrations exceeding the asserted plan's limits, and resetting the scheduled-post cron when the asserted plan was the free tier. Impact is limited to the attacker's own organization and cannot be redirected at other tenants through this endpoint. This issue has been fixed in version 2.21.8.

PUBLISHED Reserved 2026-05-22 | Published 2026-06-16 | Updated 2026-06-17 | Assigner GitHub_M




MEDIUM: 4.8CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:L

Problem types

CWE-345: Insufficient Verification of Data Authenticity

CWE-639: Authorization Bypass Through User-Controlled Key

CWE-749: Exposed Dangerous Method or Function

CWE-862: Missing Authorization

Product status

< 2.21.8
affected

References

github.com/...iz-app/security/advisories/GHSA-v4wr-4j8g-4hfj

github.com/...ommit/23696d2973510ae1f3f48bfa41a6bfbbf9827b05

gadvisory.org/advisories/PSA-2026-WWFR8X

github.com/gitroomhq/postiz-app/releases/tag/v2.21.8

cve.org (CVE-2026-48783)

nvd.nist.gov (CVE-2026-48783)

Download JSON