{"containers":{"cna":{"affected":[{"collectionURL":"https://repo.hex.pm","cpes":["cpe:2.3:a:rrrene:html_sanitize_ex:*:*:*:*:*:*:*:*"],"defaultStatus":"unaffected","modules":["Elixir.HtmlSanitizeEx.Scrubber.HTML5","Elixir.HtmlSanitizeEx"],"packageName":"html_sanitize_ex","packageURL":"pkg:hex/html_sanitize_ex","product":"html_sanitize_ex","programFiles":["lib/html_sanitize_ex/scrubber/html5.ex","lib/html_sanitize_ex.ex"],"programRoutines":[{"name":"'Elixir.HtmlSanitizeEx.Scrubber.HTML5':scrub_attribute/2"},{"name":"'Elixir.HtmlSanitizeEx.Scrubber.HTML5':sanitize/1"},{"name":"'Elixir.HtmlSanitizeEx':html5/1"}],"repo":"https://github.com/rrrene/html_sanitize_ex","vendor":"rrrene","versions":[{"lessThan":"1.5.3","status":"affected","version":"0.3.1","versionType":"semver"}]},{"collectionURL":"https://github.com","cpes":["cpe:2.3:a:rrrene:html_sanitize_ex:*:*:*:*:*:*:*:*"],"defaultStatus":"unaffected","modules":["Elixir.HtmlSanitizeEx.Scrubber.HTML5","Elixir.HtmlSanitizeEx"],"packageName":"rrrene/html_sanitize_ex","packageURL":"pkg:github/rrrene/html_sanitize_ex","product":"html_sanitize_ex","programFiles":["lib/html_sanitize_ex/scrubber/html5.ex","lib/html_sanitize_ex.ex"],"programRoutines":[{"name":"'Elixir.HtmlSanitizeEx.Scrubber.HTML5':scrub_attribute/2"},{"name":"'Elixir.HtmlSanitizeEx.Scrubber.HTML5':sanitize/1"},{"name":"'Elixir.HtmlSanitizeEx':html5/1"}],"repo":"https://github.com/rrrene/html_sanitize_ex","vendor":"rrrene","versions":[{"lessThan":"bec27fec4de99e40c68c4285a610e09e791a3eaf","status":"affected","version":"8976d64ea0b77d26093a94a43ec48a3978e8d028","versionType":"git"}]}],"configurations":[{"lang":"en","supportingMedia":[{"base64":false,"type":"text/html","value":"<p>Only <code>HtmlSanitizeEx.html5/1</code>, and custom scrubbers declared with <code>use HtmlSanitizeEx, extend: :html5</code>, allow the <code>object</code> element, and the sanitized output must be rendered to other users.</p>\n<p>Script execution in the host origin additionally requires the application to serve attacker-controlled HTML from a same-origin path, such as an uploads directory served as <code>text/html</code>.</p>"},{"base64":false,"type":"text/markdown","value":"Only `HtmlSanitizeEx.html5/1`, and custom scrubbers declared with `use HtmlSanitizeEx, extend: :html5`, allow the `object` element, and the sanitized output must be rendered to other users.\n\nScript execution in the host origin additionally requires the application to serve attacker-controlled HTML from a same-origin path, such as an uploads directory served as `text/html`."}],"value":"Only HtmlSanitizeEx.html5/1, and custom scrubbers declared with use HtmlSanitizeEx, extend: :html5, allow the object element, and the sanitized output must be rendered to other users.\n\nScript execution in the host origin additionally requires the application to serve attacker-controlled HTML from a same-origin path, such as an uploads directory served as text/html."}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:a:rrrene:html_sanitize_ex:*:*:*:*:*:*:*:*","versionEndExcluding":"1.5.3","versionStartIncluding":"0.3.1","vulnerable":true}],"negate":false,"operator":"OR"}],"operator":"AND"}],"credits":[{"lang":"en","type":"finder","value":"Peter Ullrich"},{"lang":"en","type":"remediation developer","value":"René Föhring"},{"lang":"en","type":"analyst","value":"Jonatan Männchen / EEF"}],"descriptions":[{"lang":"en","supportingMedia":[{"base64":false,"type":"text/html","value":"<p>Inclusion of Functionality from Untrusted Control Sphere vulnerability in the HTML5 scrubber in rrrene html_sanitize_ex allows a remote attacker to load a document of their choosing into a trusted page via the <code>data</code> attribute of an <code>&lt;object&gt;</code> element in sanitized HTML. <code>object</code> is the one URI-bearing element in <code>lib/html_sanitize_ex/scrubber/html5.ex</code> never registered through <code>allow_tag_with_uri_attributes/3</code>, and its only guard is a prefix match on lowercase <code>\"javascript:\"</code>, so mixed-case variants, <code>data:</code> URIs, protocol-relative URLs and same-origin paths all survive.</p>\n<p>This is not unconditional cross-site scripting. A <code>javascript:</code> URL does not execute through <code>&lt;object data&gt;</code> in current browsers, <code>data:</code> documents load in an opaque origin, and host-origin script execution additionally requires the application to serve attacker-controlled content from a same-origin path.</p>\n<p>This issue affects html_sanitize_ex: from 0.3.1 before 1.5.3.</p>"},{"base64":false,"type":"text/markdown","value":"Inclusion of Functionality from Untrusted Control Sphere vulnerability in the HTML5 scrubber in rrrene html_sanitize_ex allows a remote attacker to load a document of their choosing into a trusted page via the `data` attribute of an `<object>` element in sanitized HTML. `object` is the one URI-bearing element in `lib/html_sanitize_ex/scrubber/html5.ex` never registered through `allow_tag_with_uri_attributes/3`, and its only guard is a prefix match on lowercase `\"javascript:\"`, so mixed-case variants, `data:` URIs, protocol-relative URLs and same-origin paths all survive.\n\nThis is not unconditional cross-site scripting. A `javascript:` URL does not execute through `<object data>` in current browsers, `data:` documents load in an opaque origin, and host-origin script execution additionally requires the application to serve attacker-controlled content from a same-origin path.\n\nThis issue affects html_sanitize_ex: from 0.3.1 before 1.5.3."}],"value":"Inclusion of Functionality from Untrusted Control Sphere vulnerability in the HTML5 scrubber in rrrene html_sanitize_ex allows a remote attacker to load a document of their choosing into a trusted page via the data attribute of an <object> element in sanitized HTML. object is the one URI-bearing element in lib/html_sanitize_ex/scrubber/html5.ex never registered through allow_tag_with_uri_attributes/3, and its only guard is a prefix match on lowercase \"javascript:\", so mixed-case variants, data: URIs, protocol-relative URLs and same-origin paths all survive.\n\nThis is not unconditional cross-site scripting. A javascript: URL does not execute through <object data> in current browsers, data: documents load in an opaque origin, and host-origin script execution additionally requires the application to serve attacker-controlled content from a same-origin path.\n\nThis issue affects html_sanitize_ex: from 0.3.1 before 1.5.3."}],"impacts":[{"capecId":"CAPEC-175","descriptions":[{"lang":"en","value":"CAPEC-175 Code Inclusion"}]}],"metrics":[{"cvssV4_0":{"Automatable":"NOT_DEFINED","Recovery":"NOT_DEFINED","Safety":"NOT_DEFINED","attackComplexity":"LOW","attackRequirements":"PRESENT","attackVector":"NETWORK","baseScore":2.3,"baseSeverity":"LOW","privilegesRequired":"NONE","providerUrgency":"NOT_DEFINED","subAvailabilityImpact":"NONE","subConfidentialityImpact":"LOW","subIntegrityImpact":"LOW","userInteraction":"PASSIVE","valueDensity":"NOT_DEFINED","vectorString":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N","version":"4.0","vulnAvailabilityImpact":"NONE","vulnConfidentialityImpact":"NONE","vulnIntegrityImpact":"NONE","vulnerabilityResponseEffort":"NOT_DEFINED"},"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}]}],"problemTypes":[{"descriptions":[{"cweId":"CWE-829","description":"CWE-829 Inclusion of Functionality from Untrusted Control Sphere","lang":"en","type":"CWE"}]}],"providerMetadata":{"dateUpdated":"2026-08-06T14:48:20.513Z","orgId":"6b3ad84c-e1a6-4bf7-a703-f496b71e49db","shortName":"EEF"},"references":[{"tags":["vendor-advisory","related"],"url":"https://github.com/rrrene/html_sanitize_ex/security/advisories/GHSA-xmm9-jc22-rcgj"},{"tags":["related"],"url":"https://cna.erlef.org/cves/CVE-2026-66843.html"},{"tags":["related"],"url":"https://osv.dev/vulnerability/EEF-CVE-2026-66843"},{"tags":["patch"],"url":"https://github.com/rrrene/html_sanitize_ex/commit/bec27fec4de99e40c68c4285a610e09e791a3eaf"}],"source":{"discovery":"EXTERNAL"},"title":"html_sanitize_ex HTML5 scrubber keeps attacker-supplied `<object>` elements, allowing untrusted content embedding","workarounds":[{"lang":"en","supportingMedia":[{"base64":false,"type":"text/html","value":"<p>Sanitize with <code>basic_html/1</code>, <code>markdown_html/1</code> or <code>strip_tags/1</code>, none of which allow <code>object</code>, or define a custom scrubber that omits it.</p>\n<p>A Content-Security-Policy of <code>object-src 'none'</code> blocks an injected <code>&lt;object&gt;</code> from loading, and hosting user uploads on a separate origin removes the escalation path.</p>"},{"base64":false,"type":"text/markdown","value":"Sanitize with `basic_html/1`, `markdown_html/1` or `strip_tags/1`, none of which allow `object`, or define a custom scrubber that omits it.\n\nA Content-Security-Policy of `object-src 'none'` blocks an injected `<object>` from loading, and hosting user uploads on a separate origin removes the escalation path."}],"value":"Sanitize with basic_html/1, markdown_html/1 or strip_tags/1, none of which allow object, or define a custom scrubber that omits it.\n\nA Content-Security-Policy of object-src 'none' blocks an injected <object> from loading, and hosting user uploads on a separate origin removes the escalation path."}]}},"cveMetadata":{"assignerOrgId":"6b3ad84c-e1a6-4bf7-a703-f496b71e49db","assignerShortName":"EEF","cveId":"CVE-2026-66843","datePublished":"2026-08-06T14:48:20.513Z","dateReserved":"2026-08-06T09:00:01.259Z","dateUpdated":"2026-08-06T14:48:20.513Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"}