{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-66296", "assignerOrgId": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db", "state": "PUBLISHED", "assignerShortName": "EEF", "dateReserved": "2026-07-24T14:10:01.114Z", "datePublished": "2026-08-03T19:04:30.556Z", "dateUpdated": "2026-08-03T19:50:27.860Z"}, "containers": {"cna": {"affected": [{"collectionURL": "https://repo.hex.pm", "cpes": ["cpe:2.3:a:lud:oaskit:*:*:*:*:*:elixir:*:*"], "defaultStatus": "unaffected", "modules": ["Elixir.Oaskit.ErrorHandler.Default"], "packageName": "oaskit", "packageURL": "pkg:hex/oaskit", "product": "oaskit", "programFiles": ["lib/oaskit/error_handler/default.ex"], "programRoutines": [{"name": "'Elixir.Oaskit.ErrorHandler.Default':format_reason/4"}, {"name": "'Elixir.Oaskit.ErrorHandler.Default':reason_to_html/1"}], "repo": "https://github.com/lud/oaskit", "vendor": "lud", "versions": [{"lessThan": "0.14.1", "status": "affected", "version": "0.1.0", "versionType": "semver"}]}, {"collectionURL": "https://github.com", "cpes": ["cpe:2.3:a:lud:oaskit:*:*:*:*:*:elixir:*:*"], "defaultStatus": "unaffected", "modules": ["Elixir.Oaskit.ErrorHandler.Default"], "packageName": "lud/oaskit", "packageURL": "pkg:github/lud/oaskit", "product": "oaskit", "programFiles": ["lib/oaskit/error_handler/default.ex"], "programRoutines": [{"name": "'Elixir.Oaskit.ErrorHandler.Default':format_reason/4"}, {"name": "'Elixir.Oaskit.ErrorHandler.Default':reason_to_html/1"}], "repo": "https://github.com/lud/oaskit", "vendor": "lud", "versions": [{"lessThan": "b70c6b2eaf0b11bdd0bbb21b8a87dbb3d46918a1", "status": "affected", "version": "552de8ca0ff60617bea58bcafa451892d61a161c", "versionType": "git"}]}], "cpeApplicability": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:a:lud:oaskit:*:*:*:*:*:elixir:*:*", "versionEndExcluding": "0.14.1", "versionStartIncluding": "0.1.0", "vulnerable": true}], "negate": false, "operator": "OR"}], "operator": "AND"}], "credits": [{"lang": "en", "type": "finder", "value": "Ludovic Dem"}, {"lang": "en", "type": "remediation developer", "value": "Ludovic Dem"}, {"lang": "en", "type": "analyst", "value": "Jonatan M\u00e4nnchen / EEF"}], "datePublic": "2026-07-05T00:00:00.000Z", "descriptions": [{"lang": "en", "supportingMedia": [{"base64": false, "type": "text/html", "value": "<p>Improper Neutralization of Input During Web Page Generation (XSS) vulnerability in lud oaskit allows reflected cross-site scripting via the default HTML error handler.</p>\n<p><code>Oaskit.ErrorHandler.Default.format_reason/4</code> and <code>Oaskit.ErrorHandler.Default.reason_to_html/1</code> in <code>lib/oaskit/error_handler/default.ex</code> render request-validation failures as an HTML page whenever the request's <code>Accept</code> header contains <code>html</code>, interpolating request-controlled strings into that page without HTML escaping. The unescaped values are object keys taken from a request body or from an object or <code>deepObject</code> query parameter, which appear in the JSON Schema error's instance path when a schema rejects them (for example under <code>additionalProperties: false</code>), and the raw <code>Content-Type</code> header, reflected in unsupported-media-type errors when it fails to parse.</p>\n<p>Because browsers send <code>Accept: text/html</code> on ordinary top-level navigation, a crafted GET link is sufficient to trigger the error page; no form submission, custom <code>Content-Type</code>, or attacker-controlled script on the victim's side is required. A payload such as <code>filter[&lt;/code&gt;&lt;/h2&gt;&lt;script&gt;alert(document.domain)&lt;/script&gt;]=x</code> terminates the enclosing markup and the injected script executes in the origin of the application using oaskit, giving it access to that origin's cookies, session, and same-origin responses.</p>\n<p>Both HTML error rendering and the vulnerable handler are enabled by default: <code>Oaskit.Plugs.ValidateRequest</code> defaults <code>:html_errors</code> to <code>true</code> and <code>:error_handler</code> to <code>Oaskit.ErrorHandler.Default</code>, so applications following the documented usage are affected without any opt-in.</p>\n<p>This issue affects oaskit: from 0.1.0 before 0.14.1.</p>"}, {"base64": false, "type": "text/markdown", "value": "Improper Neutralization of Input During Web Page Generation (XSS) vulnerability in lud oaskit allows reflected cross-site scripting via the default HTML error handler.\n\n`Oaskit.ErrorHandler.Default.format_reason/4` and `Oaskit.ErrorHandler.Default.reason_to_html/1` in `lib/oaskit/error_handler/default.ex` render request-validation failures as an HTML page whenever the request's `Accept` header contains `html`, interpolating request-controlled strings into that page without HTML escaping. The unescaped values are object keys taken from a request body or from an object or `deepObject` query parameter, which appear in the JSON Schema error's instance path when a schema rejects them (for example under `additionalProperties: false`), and the raw `Content-Type` header, reflected in unsupported-media-type errors when it fails to parse.\n\nBecause browsers send `Accept: text/html` on ordinary top-level navigation, a crafted GET link is sufficient to trigger the error page; no form submission, custom `Content-Type`, or attacker-controlled script on the victim's side is required. A payload such as `filter[</code></h2><script>alert(document.domain)</script>]=x` terminates the enclosing markup and the injected script executes in the origin of the application using oaskit, giving it access to that origin's cookies, session, and same-origin responses.\n\nBoth HTML error rendering and the vulnerable handler are enabled by default: `Oaskit.Plugs.ValidateRequest` defaults `:html_errors` to `true` and `:error_handler` to `Oaskit.ErrorHandler.Default`, so applications following the documented usage are affected without any opt-in.\n\nThis issue affects oaskit: from 0.1.0 before 0.14.1."}], "value": "Improper Neutralization of Input During Web Page Generation (XSS) vulnerability in lud oaskit allows reflected cross-site scripting via the default HTML error handler.\n\nOaskit.ErrorHandler.Default.format_reason/4 and Oaskit.ErrorHandler.Default.reason_to_html/1 in lib/oaskit/error_handler/default.ex render request-validation failures as an HTML page whenever the request's Accept header contains html, interpolating request-controlled strings into that page without HTML escaping. The unescaped values are object keys taken from a request body or from an object or deepObject query parameter, which appear in the JSON Schema error's instance path when a schema rejects them (for example under additionalProperties: false), and the raw Content-Type header, reflected in unsupported-media-type errors when it fails to parse.\n\nBecause browsers send Accept: text/html on ordinary top-level navigation, a crafted GET link is sufficient to trigger the error page; no form submission, custom Content-Type, or attacker-controlled script on the victim's side is required. A payload such as filter[</code></h2><script>alert(document.domain)</script>]=x terminates the enclosing markup and the injected script executes in the origin of the application using oaskit, giving it access to that origin's cookies, session, and same-origin responses.\n\nBoth HTML error rendering and the vulnerable handler are enabled by default: Oaskit.Plugs.ValidateRequest defaults :html_errors to true and :error_handler to Oaskit.ErrorHandler.Default, so applications following the documented usage are affected without any opt-in.\n\nThis issue affects oaskit: from 0.1.0 before 0.14.1."}], "impacts": [{"capecId": "CAPEC-591", "descriptions": [{"lang": "en", "value": "CAPEC-591 Reflected XSS"}]}], "metrics": [{"cvssV4_0": {"Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "Safety": "NOT_DEFINED", "attackComplexity": "LOW", "attackRequirements": "NONE", "attackVector": "NETWORK", "baseScore": 5.1, "baseSeverity": "MEDIUM", "privilegesRequired": "NONE", "providerUrgency": "NOT_DEFINED", "subAvailabilityImpact": "NONE", "subConfidentialityImpact": "LOW", "subIntegrityImpact": "LOW", "userInteraction": "ACTIVE", "valueDensity": "NOT_DEFINED", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/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-79", "description": "CWE-79 Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')", "lang": "en", "type": "CWE"}]}], "providerMetadata": {"orgId": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db", "shortName": "EEF", "dateUpdated": "2026-08-03T19:04:30.556Z"}, "references": [{"tags": ["vendor-advisory", "related"], "url": "https://github.com/lud/oaskit/security/advisories/GHSA-h7xw-x8wr-xpcc"}, {"tags": ["related"], "url": "https://cna.erlef.org/cves/CVE-2026-66296.html"}, {"tags": ["related"], "url": "https://osv.dev/vulnerability/EEF-CVE-2026-66296"}, {"tags": ["patch"], "url": "https://github.com/lud/oaskit/commit/b70c6b2eaf0b11bdd0bbb21b8a87dbb3d46918a1"}], "source": {"discovery": "INTERNAL"}, "title": "Reflected XSS in oaskit's default HTML error handler", "workarounds": [{"lang": "en", "supportingMedia": [{"base64": false, "type": "text/html", "value": "<p>Disable HTML error rendering so that validation failures are returned as JSON only:</p>\n<pre><code class=\"language-elixir\">plug Oaskit.Plugs.ValidateRequest, html_errors: false\n</code></pre>\n<p>This prevents the vulnerable HTML page from being rendered at all, on any oaskit version. Alternatively, configure a custom <code>:error_handler</code> that does not emit HTML built from request-derived values.</p>"}, {"base64": false, "type": "text/markdown", "value": "Disable HTML error rendering so that validation failures are returned as JSON only:\n\n```elixir\nplug Oaskit.Plugs.ValidateRequest, html_errors: false\n```\n\nThis prevents the vulnerable HTML page from being rendered at all, on any oaskit version. Alternatively, configure a custom `:error_handler` that does not emit HTML built from request-derived values."}], "value": "Disable HTML error rendering so that validation failures are returned as JSON only:\n\nplug Oaskit.Plugs.ValidateRequest, html_errors: false\n\nThis prevents the vulnerable HTML page from being rendered at all, on any oaskit version. Alternatively, configure a custom :error_handler that does not emit HTML built from request-derived values."}]}, "adp": [{"references": [{"url": "https://github.com/lud/oaskit/security/advisories/GHSA-h7xw-x8wr-xpcc", "tags": ["exploit"]}], "metrics": [{"other": {"type": "ssvc", "content": {"timestamp": "2026-08-03T19:50:03.665445Z", "id": "CVE-2026-66296", "options": [{"Exploitation": "poc"}, {"Automatable": "no"}, {"Technical Impact": "partial"}], "role": "CISA Coordinator", "version": "2.0.3"}}}], "title": "CISA ADP Vulnrichment", "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-08-03T19:50:27.860Z"}}]}}

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-66296", "assignerOrgId": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db", "state": "PUBLISHED", "assignerShortName": "EEF", "dateReserved": "2026-07-24T14:10:01.114Z", "datePublished": "2026-08-03T19:04:30.556Z", "dateUpdated": "2026-08-03T19:50:27.860Z"}, "containers": {"cna": {"affected": [{"collectionURL": "https://repo.hex.pm", "cpes": ["cpe:2.3:a:lud:oaskit:*:*:*:*:*:elixir:*:*"], "defaultStatus": "unaffected", "modules": ["Elixir.Oaskit.ErrorHandler.Default"], "packageName": "oaskit", "packageURL": "pkg:hex/oaskit", "product": "oaskit", "programFiles": ["lib/oaskit/error_handler/default.ex"], "programRoutines": [{"name": "'Elixir.Oaskit.ErrorHandler.Default':format_reason/4"}, {"name": "'Elixir.Oaskit.ErrorHandler.Default':reason_to_html/1"}], "repo": "https://github.com/lud/oaskit", "vendor": "lud", "versions": [{"lessThan": "0.14.1", "status": "affected", "version": "0.1.0", "versionType": "semver"}]}, {"collectionURL": "https://github.com", "cpes": ["cpe:2.3:a:lud:oaskit:*:*:*:*:*:elixir:*:*"], "defaultStatus": "unaffected", "modules": ["Elixir.Oaskit.ErrorHandler.Default"], "packageName": "lud/oaskit", "packageURL": "pkg:github/lud/oaskit", "product": "oaskit", "programFiles": ["lib/oaskit/error_handler/default.ex"], "programRoutines": [{"name": "'Elixir.Oaskit.ErrorHandler.Default':format_reason/4"}, {"name": "'Elixir.Oaskit.ErrorHandler.Default':reason_to_html/1"}], "repo": "https://github.com/lud/oaskit", "vendor": "lud", "versions": [{"lessThan": "b70c6b2eaf0b11bdd0bbb21b8a87dbb3d46918a1", "status": "affected", "version": "552de8ca0ff60617bea58bcafa451892d61a161c", "versionType": "git"}]}], "cpeApplicability": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:a:lud:oaskit:*:*:*:*:*:elixir:*:*", "versionEndExcluding": "0.14.1", "versionStartIncluding": "0.1.0", "vulnerable": true}], "negate": false, "operator": "OR"}], "operator": "AND"}], "credits": [{"lang": "en", "type": "finder", "value": "Ludovic Dem"}, {"lang": "en", "type": "remediation developer", "value": "Ludovic Dem"}, {"lang": "en", "type": "analyst", "value": "Jonatan M\u00e4nnchen / EEF"}], "datePublic": "2026-07-05T00:00:00.000Z", "descriptions": [{"lang": "en", "supportingMedia": [{"base64": false, "type": "text/html", "value": "<p>Improper Neutralization of Input During Web Page Generation (XSS) vulnerability in lud oaskit allows reflected cross-site scripting via the default HTML error handler.</p>\n<p><code>Oaskit.ErrorHandler.Default.format_reason/4</code> and <code>Oaskit.ErrorHandler.Default.reason_to_html/1</code> in <code>lib/oaskit/error_handler/default.ex</code> render request-validation failures as an HTML page whenever the request's <code>Accept</code> header contains <code>html</code>, interpolating request-controlled strings into that page without HTML escaping. The unescaped values are object keys taken from a request body or from an object or <code>deepObject</code> query parameter, which appear in the JSON Schema error's instance path when a schema rejects them (for example under <code>additionalProperties: false</code>), and the raw <code>Content-Type</code> header, reflected in unsupported-media-type errors when it fails to parse.</p>\n<p>Because browsers send <code>Accept: text/html</code> on ordinary top-level navigation, a crafted GET link is sufficient to trigger the error page; no form submission, custom <code>Content-Type</code>, or attacker-controlled script on the victim's side is required. A payload such as <code>filter[&lt;/code&gt;&lt;/h2&gt;&lt;script&gt;alert(document.domain)&lt;/script&gt;]=x</code> terminates the enclosing markup and the injected script executes in the origin of the application using oaskit, giving it access to that origin's cookies, session, and same-origin responses.</p>\n<p>Both HTML error rendering and the vulnerable handler are enabled by default: <code>Oaskit.Plugs.ValidateRequest</code> defaults <code>:html_errors</code> to <code>true</code> and <code>:error_handler</code> to <code>Oaskit.ErrorHandler.Default</code>, so applications following the documented usage are affected without any opt-in.</p>\n<p>This issue affects oaskit: from 0.1.0 before 0.14.1.</p>"}, {"base64": false, "type": "text/markdown", "value": "Improper Neutralization of Input During Web Page Generation (XSS) vulnerability in lud oaskit allows reflected cross-site scripting via the default HTML error handler.\n\n`Oaskit.ErrorHandler.Default.format_reason/4` and `Oaskit.ErrorHandler.Default.reason_to_html/1` in `lib/oaskit/error_handler/default.ex` render request-validation failures as an HTML page whenever the request's `Accept` header contains `html`, interpolating request-controlled strings into that page without HTML escaping. The unescaped values are object keys taken from a request body or from an object or `deepObject` query parameter, which appear in the JSON Schema error's instance path when a schema rejects them (for example under `additionalProperties: false`), and the raw `Content-Type` header, reflected in unsupported-media-type errors when it fails to parse.\n\nBecause browsers send `Accept: text/html` on ordinary top-level navigation, a crafted GET link is sufficient to trigger the error page; no form submission, custom `Content-Type`, or attacker-controlled script on the victim's side is required. A payload such as `filter[</code></h2><script>alert(document.domain)</script>]=x` terminates the enclosing markup and the injected script executes in the origin of the application using oaskit, giving it access to that origin's cookies, session, and same-origin responses.\n\nBoth HTML error rendering and the vulnerable handler are enabled by default: `Oaskit.Plugs.ValidateRequest` defaults `:html_errors` to `true` and `:error_handler` to `Oaskit.ErrorHandler.Default`, so applications following the documented usage are affected without any opt-in.\n\nThis issue affects oaskit: from 0.1.0 before 0.14.1."}], "value": "Improper Neutralization of Input During Web Page Generation (XSS) vulnerability in lud oaskit allows reflected cross-site scripting via the default HTML error handler.\n\nOaskit.ErrorHandler.Default.format_reason/4 and Oaskit.ErrorHandler.Default.reason_to_html/1 in lib/oaskit/error_handler/default.ex render request-validation failures as an HTML page whenever the request's Accept header contains html, interpolating request-controlled strings into that page without HTML escaping. The unescaped values are object keys taken from a request body or from an object or deepObject query parameter, which appear in the JSON Schema error's instance path when a schema rejects them (for example under additionalProperties: false), and the raw Content-Type header, reflected in unsupported-media-type errors when it fails to parse.\n\nBecause browsers send Accept: text/html on ordinary top-level navigation, a crafted GET link is sufficient to trigger the error page; no form submission, custom Content-Type, or attacker-controlled script on the victim's side is required. A payload such as filter[</code></h2><script>alert(document.domain)</script>]=x terminates the enclosing markup and the injected script executes in the origin of the application using oaskit, giving it access to that origin's cookies, session, and same-origin responses.\n\nBoth HTML error rendering and the vulnerable handler are enabled by default: Oaskit.Plugs.ValidateRequest defaults :html_errors to true and :error_handler to Oaskit.ErrorHandler.Default, so applications following the documented usage are affected without any opt-in.\n\nThis issue affects oaskit: from 0.1.0 before 0.14.1."}], "impacts": [{"capecId": "CAPEC-591", "descriptions": [{"lang": "en", "value": "CAPEC-591 Reflected XSS"}]}], "metrics": [{"cvssV4_0": {"Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "Safety": "NOT_DEFINED", "attackComplexity": "LOW", "attackRequirements": "NONE", "attackVector": "NETWORK", "baseScore": 5.1, "baseSeverity": "MEDIUM", "privilegesRequired": "NONE", "providerUrgency": "NOT_DEFINED", "subAvailabilityImpact": "NONE", "subConfidentialityImpact": "LOW", "subIntegrityImpact": "LOW", "userInteraction": "ACTIVE", "valueDensity": "NOT_DEFINED", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/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-79", "description": "CWE-79 Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')", "lang": "en", "type": "CWE"}]}], "providerMetadata": {"orgId": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db", "shortName": "EEF", "dateUpdated": "2026-08-03T19:04:30.556Z"}, "references": [{"tags": ["vendor-advisory", "related"], "url": "https://github.com/lud/oaskit/security/advisories/GHSA-h7xw-x8wr-xpcc"}, {"tags": ["related"], "url": "https://cna.erlef.org/cves/CVE-2026-66296.html"}, {"tags": ["related"], "url": "https://osv.dev/vulnerability/EEF-CVE-2026-66296"}, {"tags": ["patch"], "url": "https://github.com/lud/oaskit/commit/b70c6b2eaf0b11bdd0bbb21b8a87dbb3d46918a1"}], "source": {"discovery": "INTERNAL"}, "title": "Reflected XSS in oaskit's default HTML error handler", "workarounds": [{"lang": "en", "supportingMedia": [{"base64": false, "type": "text/html", "value": "<p>Disable HTML error rendering so that validation failures are returned as JSON only:</p>\n<pre><code class=\"language-elixir\">plug Oaskit.Plugs.ValidateRequest, html_errors: false\n</code></pre>\n<p>This prevents the vulnerable HTML page from being rendered at all, on any oaskit version. Alternatively, configure a custom <code>:error_handler</code> that does not emit HTML built from request-derived values.</p>"}, {"base64": false, "type": "text/markdown", "value": "Disable HTML error rendering so that validation failures are returned as JSON only:\n\n```elixir\nplug Oaskit.Plugs.ValidateRequest, html_errors: false\n```\n\nThis prevents the vulnerable HTML page from being rendered at all, on any oaskit version. Alternatively, configure a custom `:error_handler` that does not emit HTML built from request-derived values."}], "value": "Disable HTML error rendering so that validation failures are returned as JSON only:\n\nplug Oaskit.Plugs.ValidateRequest, html_errors: false\n\nThis prevents the vulnerable HTML page from being rendered at all, on any oaskit version. Alternatively, configure a custom :error_handler that does not emit HTML built from request-derived values."}]}, "adp": [{"title": "CISA ADP Vulnrichment", "metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2026-66296", "role": "CISA Coordinator", "options": [{"Exploitation": "poc"}, {"Automatable": "no"}, {"Technical Impact": "partial"}], "version": "2.0.3", "timestamp": "2026-08-03T19:50:03.665445Z"}}}], "references": [{"url": "https://github.com/lud/oaskit/security/advisories/GHSA-h7xw-x8wr-xpcc", "tags": ["exploit"]}], "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-08-03T19:50:23.782Z"}}]}}

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