{"id":"CVE-2026-8467","state":"PUBLISHED","title":"Unauthenticated remote code execution via HEEx template injection in phoenix_storybook playground","description":"Code Injection vulnerability in phenixdigital phoenix_storybook allows unauthenticated remote code execution via unsanitized attribute value interpolation in HEEx template generation.\n\nThe 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.\n\nThis issue affects phoenix_storybook from 0.5.0 before 1.1.0.","publishedAt":"2026-05-20T13:35:29.018Z","updatedAt":"2026-05-27T15:41:02.357Z","severity":{"score":9.5,"label":"Critical","version":"4.0","vector":"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","source":"EEF"},"assigner":"EEF","products":["phenixdigital phoenix_storybook"],"affected":[{"vendor":"phenixdigital","product":"phoenix_storybook","packageName":"phoenix_storybook","packageURL":"pkg:hex/phoenix_storybook","defaultStatus":"unaffected","versions":[{"version":"0.5.0","status":"affected","lessThan":"1.1.0","versionType":"semver"}],"collectionURL":"https://repo.hex.pm","cpes":["cpe:2.3:a:phenixdigital:phoenix_storybook:*:*:*:*:*:*:*:*"],"modules":["Elixir.PhoenixStorybook.Rendering.ComponentRenderer","Elixir.PhoenixStorybook.Story.PlaygroundPreviewLive","Elixir.PhoenixStorybook.Helpers.ExtraAssignsHelpers"],"programFiles":["lib/phoenix_storybook/rendering/component_renderer.ex","lib/phoenix_storybook/live/story/playground_preview_live.ex","lib/phoenix_storybook/helpers/extra_assigns_helpers.ex"],"programRoutines":[{"name":"'Elixir.PhoenixStorybook.Rendering.ComponentRenderer':attributes_markup/1"},{"name":"'Elixir.PhoenixStorybook.Story.PlaygroundPreviewLive':handle_event/3"},{"name":"'Elixir.PhoenixStorybook.Helpers.ExtraAssignsHelpers':handle_set_variation_assign/3"}],"repo":"https://github.com/phenixdigital/phoenix_storybook"},{"vendor":"phenixdigital","product":"phoenix_storybook","packageName":"phenixdigital/phoenix_storybook","packageURL":"pkg:github/phenixdigital/phoenix_storybook","defaultStatus":"unaffected","versions":[{"version":"e35379dfe2ef1a71b141899e36f431017c55265d","status":"affected","lessThan":"56ab8464d4375fa52db806148a06cce126ad481d","versionType":"git"}],"collectionURL":"https://github.com","cpes":["cpe:2.3:a:phenixdigital:phoenix_storybook:*:*:*:*:*:*:*:*"],"modules":["Elixir.PhoenixStorybook.Rendering.ComponentRenderer","Elixir.PhoenixStorybook.Story.PlaygroundPreviewLive","Elixir.PhoenixStorybook.Helpers.ExtraAssignsHelpers"],"programFiles":["lib/phoenix_storybook/rendering/component_renderer.ex","lib/phoenix_storybook/live/story/playground_preview_live.ex","lib/phoenix_storybook/helpers/extra_assigns_helpers.ex"],"programRoutines":[{"name":"'Elixir.PhoenixStorybook.Rendering.ComponentRenderer':attributes_markup/1"},{"name":"'Elixir.PhoenixStorybook.Story.PlaygroundPreviewLive':handle_event/3"},{"name":"'Elixir.PhoenixStorybook.Helpers.ExtraAssignsHelpers':handle_set_variation_assign/3"}],"repo":"https://github.com/phenixdigital/phoenix_storybook"}],"references":["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"],"weaknesses":["CWE-94"],"ingestedAt":"2026-10-29T20:13:26.108Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/8xxx/CVE-2026-8467.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-8467","state":"PUBLISHED","datePublished":"2026-05-20T13:35:29.018Z","dateUpdated":"2026-05-27T15:41:02.357Z","assignerShortName":"EEF","assignerOrgId":"6b3ad84c-e1a6-4bf7-a703-f496b71e49db","dateReserved":"2026-05-13T11:44:40.790Z"},"containers":{"cna":{"title":"Unauthenticated remote code execution via HEEx template injection in phoenix_storybook playground","descriptions":[{"lang":"en","value":"Code Injection vulnerability in phenixdigital phoenix_storybook allows unauthenticated remote code execution via unsanitized attribute value interpolation in HEEx template generation.\n\nThe 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.\n\nThis issue affects phoenix_storybook from 0.5.0 before 1.1.0."}],"affected":[{"vendor":"phenixdigital","product":"phoenix_storybook","packageName":"phoenix_storybook","packageURL":"pkg:hex/phoenix_storybook","defaultStatus":"unaffected","versions":[{"version":"0.5.0","status":"affected","lessThan":"1.1.0","versionType":"semver"}],"collectionURL":"https://repo.hex.pm","cpes":["cpe:2.3:a:phenixdigital:phoenix_storybook:*:*:*:*:*:*:*:*"],"modules":["Elixir.PhoenixStorybook.Rendering.ComponentRenderer","Elixir.PhoenixStorybook.Story.PlaygroundPreviewLive","Elixir.PhoenixStorybook.Helpers.ExtraAssignsHelpers"],"programFiles":["lib/phoenix_storybook/rendering/component_renderer.ex","lib/phoenix_storybook/live/story/playground_preview_live.ex","lib/phoenix_storybook/helpers/extra_assigns_helpers.ex"],"programRoutines":[{"name":"'Elixir.PhoenixStorybook.Rendering.ComponentRenderer':attributes_markup/1"},{"name":"'Elixir.PhoenixStorybook.Story.PlaygroundPreviewLive':handle_event/3"},{"name":"'Elixir.PhoenixStorybook.Helpers.ExtraAssignsHelpers':handle_set_variation_assign/3"}],"repo":"https://github.com/phenixdigital/phoenix_storybook"},{"vendor":"phenixdigital","product":"phoenix_storybook","packageName":"phenixdigital/phoenix_storybook","packageURL":"pkg:github/phenixdigital/phoenix_storybook","defaultStatus":"unaffected","versions":[{"version":"e35379dfe2ef1a71b141899e36f431017c55265d","status":"affected","lessThan":"56ab8464d4375fa52db806148a06cce126ad481d","versionType":"git"}],"collectionURL":"https://github.com","cpes":["cpe:2.3:a:phenixdigital:phoenix_storybook:*:*:*:*:*:*:*:*"],"modules":["Elixir.PhoenixStorybook.Rendering.ComponentRenderer","Elixir.PhoenixStorybook.Story.PlaygroundPreviewLive","Elixir.PhoenixStorybook.Helpers.ExtraAssignsHelpers"],"programFiles":["lib/phoenix_storybook/rendering/component_renderer.ex","lib/phoenix_storybook/live/story/playground_preview_live.ex","lib/phoenix_storybook/helpers/extra_assigns_helpers.ex"],"programRoutines":[{"name":"'Elixir.PhoenixStorybook.Rendering.ComponentRenderer':attributes_markup/1"},{"name":"'Elixir.PhoenixStorybook.Story.PlaygroundPreviewLive':handle_event/3"},{"name":"'Elixir.PhoenixStorybook.Helpers.ExtraAssignsHelpers':handle_set_variation_assign/3"}],"repo":"https://github.com/phenixdigital/phoenix_storybook"}],"references":[{"url":"https://github.com/phenixdigital/phoenix_storybook/security/advisories/GHSA-55hg-8qxv-qj4p","tags":["vendor-advisory","related"]},{"url":"https://cna.erlef.org/cves/CVE-2026-8467.html","tags":["related"]},{"url":"https://osv.dev/vulnerability/EEF-CVE-2026-8467","tags":["related"]},{"url":"https://github.com/phenixdigital/phoenix_storybook/commit/56ab8464d4375fa52db806148a06cce126ad481d","tags":["patch"]}],"metrics":[{"cvssV4_0":{"attackComplexity":"LOW","attackRequirements":"PRESENT","attackVector":"NETWORK","baseScore":9.5,"baseSeverity":"CRITICAL","privilegesRequired":"NONE","subAvailabilityImpact":"HIGH","subConfidentialityImpact":"HIGH","subIntegrityImpact":"HIGH","userInteraction":"NONE","vectorString":"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","version":"4.0","vulnAvailabilityImpact":"HIGH","vulnConfidentialityImpact":"HIGH","vulnIntegrityImpact":"HIGH"},"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}]}],"problemTypes":[{"descriptions":[{"cweId":"CWE-94","description":"CWE-94 Improper Control of Generation of Code ('Code Injection')","lang":"en","type":"CWE"}]}],"providerMetadata":{"shortName":"EEF","orgId":"6b3ad84c-e1a6-4bf7-a703-f496b71e49db","dateUpdated":"2026-05-27T15:41:02.357Z"},"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:a:phenixdigital:phoenix_storybook:*:*:*:*:*:*:*:*","versionEndExcluding":"1.1.0","versionStartIncluding":"0.5.0","vulnerable":true}],"negate":false,"operator":"OR"}]}],"credits":[{"lang":"en","type":"finder","value":"Nick Mykhailyshyn"},{"lang":"en","type":"analyst","value":"Cenk Kücük"},{"lang":"en","type":"remediation developer","value":"Christian Blavier"},{"lang":"en","type":"analyst","value":"Jonatan Männchen / EEF"}],"impacts":[{"capecId":"CAPEC-242","descriptions":[{"lang":"en","value":"CAPEC-242 Code Injection"}]}],"source":{"discovery":"EXTERNAL"},"x_generator":{"engine":"cvelib 1.8.0"}},"adp":[{"title":"CISA ADP Vulnrichment","references":[{"url":"https://github.com/phenixdigital/phoenix_storybook/security/advisories/GHSA-55hg-8qxv-qj4p","tags":["exploit"]}],"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-05-21T13:57:52.803277Z","id":"CVE-2026-8467","options":[{"Exploitation":"poc"},{"Automatable":"yes"},{"Technical Impact":"total"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-05-21T13:58:36.035Z"}}]}}}