Weakness Type (CWE)

CWE-94 — CWE-94 Improper Control of Generation of Code ('Code Injection')

CAPEC

CVSS 4.0 Score

9.5

CRITICAL

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

Vulnerability description

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="<val>" 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.

Affected

pkg:hex/phoenix_storybook

Module Source File Routine
Elixir.PhoenixStorybook.Rendering.ComponentRenderer lib/phoenix_storybook/rendering/component_renderer.ex PhoenixStorybook.Rendering.ComponentRenderer.attributes_markup/1
Elixir.PhoenixStorybook.Story.PlaygroundPreviewLive lib/phoenix_storybook/live/story/playground_preview_live.ex PhoenixStorybook.Story.PlaygroundPreviewLive.handle_event/3
Elixir.PhoenixStorybook.Helpers.ExtraAssignsHelpers lib/phoenix_storybook/helpers/extra_assigns_helpers.ex PhoenixStorybook.Helpers.ExtraAssignsHelpers.handle_set_variation_assign/3
Status Type Version Changes / Fixed in
affected semver ⓘ 0.5.0 < 1.1.0

pkg:github/phenixdigital/phoenix_storybook

Module Source File Routine
Elixir.PhoenixStorybook.Rendering.ComponentRenderer lib/phoenix_storybook/rendering/component_renderer.ex PhoenixStorybook.Rendering.ComponentRenderer.attributes_markup/1
Elixir.PhoenixStorybook.Story.PlaygroundPreviewLive lib/phoenix_storybook/live/story/playground_preview_live.ex PhoenixStorybook.Story.PlaygroundPreviewLive.handle_event/3
Elixir.PhoenixStorybook.Helpers.ExtraAssignsHelpers lib/phoenix_storybook/helpers/extra_assigns_helpers.ex PhoenixStorybook.Helpers.ExtraAssignsHelpers.handle_set_variation_assign/3
Status Type Version Changes / Fixed in
affected git ⓘ e35379dfe2 < 56ab8464d4

References

Credits

  • Finder: Nick Mykhailyshyn
  • Analyst: Cenk Kücük
  • Remediation developer: Christian Blavier
  • Coordinator: Jonatan Männchen

CVE record as JSON:  GET /cves/CVE-2026-8467.json
OSV record as JSON:  GET /osv/EEF-CVE-2026-8467.json