---
cve: "CVE-2026-8467"
severity: "CRITICAL"
cvss: 9.5
epss: "2.1%"
vendor: "phenixdigital"
kev: false
exploited: false
published: "2026-05-20 14:17:04"
tags: [cve, security, critical]
source: tsecurity.de CVE-Dossier
exported: "2026-10-10T10:15:40+02:00"
---

# CVE-2026-8467

> 9.5 CRITICAL · 🧪 PoC

## Beschreibung

Code Injection vulnerability in phenixdigital phoenix_storybook allows unauthenticated remote code execution via unsanitized attribute value interpolation in HEEx template generation.

The psb-assign WebSocket event handler in 'Elixir.PhoenixStorybook.Story.PlaygroundPreviewLive':handle_event/3 accepts arbitrary attribute names and values from unauthenticated clients. These values are passed to 'Elixir.PhoenixStorybook.Helpers.ExtraAssignsHelpers':handle_set_variation_assign/3, which stores them verbatim. When rendering, 'Elixir.PhoenixStorybook.Rendering.ComponentRenderer':attributes_markup/1 interpolates binary attribute values directly into a HEEx template string as name="" without escaping double quotes or HEEx expression delimiters. An attacker can supply a value containing a closing quote followed by a HEEx expression block (e.g. foo" injected={EXPR} bar="), which causes EXPR to be treated as an inline Elixir expression. The resulting template is compiled via EEx.compile_string/2 and executed via Code.eval_quoted_with_env/3 with full Kernel imports and no sandbox, giving the attacker arbitrary code execution on the server.

This issue affects phoenix_storybook from 0.5.0 before 1.1.0.

## CISA-Anreicherung (vulnrichment/ADP)

- CISA-SSVC (Coordinator, v2.0.3):
  - Exploitation: **poc**
  - Automatable: **yes**
  - Technical Impact: **total**

## CVSS-Vektor

```
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H
```

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Netzwerk | bad |
| AC Komplexität | Gering | bad |
| PR Privilegien | Keine | bad |
| UI Interaktion | Keine | bad |

## Patch verfügbar (OSV)

- 56ab8464d4375fa52db806148a06cce126ad481d (Commit)
- 685e23efc81afd9bc921d4afa984fff34c4b7e55 (Commit)

## Referenzen

- <https://github.com/phenixdigital/phoenix_storybook/security/advisories/GHSA-55hg-8qxv-qj4p>
- <https://cna.erlef.org/cves/CVE-2026-8467.html>
- <https://osv.dev/vulnerability/EEF-CVE-2026-8467>
- <https://github.com/phenixdigital/phoenix_storybook/commit/56ab8464d4375fa52db806148a06cce126ad481d>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/sicherheitsluecken/cve-2026-8467/) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI WID (CSAF)_