# CVE-2026-48783: Postiz has an unauthenticated billing-enforcement bypass via /public/modify-subscription

> Unauthenticated users can bypass billing enforcement to disable integrations and reset schedules within their own organization.

- **Severity:** Medium 4.8 (`CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 16 Jun 2026
- **Updated:** 17 Jun 2026
- **Also known as:** GHSA-v4wr-4j8g-4hfj

## What is CVE-2026-48783?

CVE-2026-48783 is a medium-severity missing authorization vulnerability in gitroomhq postiz-app, published on 16 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official 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.

Weakness: CWE-862 (Missing Authorization), CWE-749 (Exposed Dangerous Method or Function), CWE-639 (Authorization Bypass Through User-Controlled Key), CWE-345 (Insufficient Verification of Data Authenticity)

## Which versions are affected by CVE-2026-48783?


## How do I fix CVE-2026-48783?

No fix has been published for CVE-2026-48783 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-48783 being exploited?

There is no known exploitation of CVE-2026-48783 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-48783 and fix it if it is affected.

What it is: CVE-2026-48783 is a medium-severity missing authorization vulnerability in gitroomhq postiz-app, published on 16 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-48783 in the wild and no public exploit code.

Affected product: gitroomhq postiz-app. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-48783/ (Markdown: https://insights.sbomify.com/CVE-2026-48783/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-48783
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-48783
- OSV: https://osv.dev/vulnerability/CVE-2026-48783

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-48783/
Summaries are generated and may contain mistakes; the official description above is the record.