# CVE-2026-47068: Cross-session PubSub topic injection via URL parameter in phoenix_storybook

> Attackers can inject their process into victim sessions via URL parameters, allowing them to intercept or manipulate private playground messages in Phoenix Storybook.

- **Severity:** Low 2.3 (`CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 20 May 2026
- **Updated:** 27 May 2026
- **Also known as:** EEF-CVE-2026-47068, GHSA-mrhx-6pw9-q5fh

## What is CVE-2026-47068?

CVE-2026-47068 is a low-severity missing authorization vulnerability in phenixdigital phoenix_storybook, published on 20 May 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

Authorization Bypass Through User-Controlled Key vulnerability in phenixdigital phoenix_storybook allows cross-session PubSub topic injection via a URL query parameter.

'Elixir.PhoenixStorybook.Story.ComponentIframeLive':handle_params/3 in lib/phoenix_storybook/live/story/component_iframe_live.ex reads a PubSub topic directly from params["topic"] and broadcasts {:component_iframe_pid, self()} on it with no check that the topic belongs to the requesting session. The shared PhoenixStorybook.PubSub is used to coordinate playground LiveViews with their iframes: a playground subscribes to a session-specific topic and uses the received iframe pid to direct subsequent control messages (variation state, theme switches, extra-assign payloads) via send/2. Because the iframe trusts the query parameter, an attacker who loads /storybook/iframe/<story>?topic=<victim_topic> causes their iframe process pid to be announced on the victim's topic. The victim's playground then addresses its private messages to the attacker's iframe process.

This issue affects phoenix_storybook from 0.4.0 before 1.1.0.

Weakness: CWE-639 (Authorization Bypass Through User-Controlled Key)

## Which versions are affected by CVE-2026-47068?

3 open source packages ship an affected version, including phoenix_storybook.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `phoenix_storybook` | Hex | From 0.4.0 | 1.1.0 |
| `phoenix_storybook` | Hex | From 0.4.0 | 1.1.0 |
| `phoenix_storybook` | Hex | From 0.4.0 | 1.1.0 |

## How do I fix CVE-2026-47068?

Upgrade phoenix_storybook to 1.1.0 or later.

## Is CVE-2026-47068 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-47068 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-47068 and fix it if it is affected.

What it is: CVE-2026-47068 is a low-severity missing authorization vulnerability in phenixdigital phoenix_storybook, published on 20 May 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-47068 exists.

Affected packages and fixed versions:
- phoenix_storybook (Hex): affected from 0.4.0; fixed in 1.1.0
- phoenix_storybook (Hex): affected from 0.4.0; fixed in 1.1.0
- phoenix_storybook (Hex): affected from 0.4.0; fixed in 1.1.0

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-2026-47068/ (Markdown: https://insights.sbomify.com/CVE-2026-47068/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-47068
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-47068
- OSV: https://osv.dev/vulnerability/CVE-2026-47068

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-47068/
Summaries are generated and may contain mistakes; the official description above is the record.