CVE-2026-66296

{"id": "CVE-2026-66296", "cveTags": [], "metrics": {"ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-66296", "role": "CISA Coordinator", "options": [{"exploitation": "poc"}, {"automatable": "no"}, {"technicalImpact": "partial"}], "version": "2.0.3", "timestamp": "2026-08-03T19:50:03.665445Z"}}], "cvssMetricV31": [{"type": "Primary", "source": "nvd@nist.gov", "cvssData": {"scope": "CHANGED", "version": "3.1", "baseScore": 6.1, "attackVector": "NETWORK", "baseSeverity": "MEDIUM", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N", "integrityImpact": "LOW", "userInteraction": "REQUIRED", "attackComplexity": "LOW", "availabilityImpact": "NONE", "privilegesRequired": "NONE", "confidentialityImpact": "LOW"}, "impactScore": 2.7, "exploitabilityScore": 2.8}], "cvssMetricV40": [{"type": "Secondary", "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db", "cvssData": {"Safety": "NOT_DEFINED", "version": "4.0", "Recovery": "NOT_DEFINED", "baseScore": 5.1, "Automatable": "NOT_DEFINED", "attackVector": "NETWORK", "baseSeverity": "MEDIUM", "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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X", "exploitMaturity": "NOT_DEFINED", "providerUrgency": "NOT_DEFINED", "userInteraction": "ACTIVE", "attackComplexity": "LOW", "attackRequirements": "NONE", "privilegesRequired": "NONE", "subIntegrityImpact": "LOW", "vulnIntegrityImpact": "NONE", "integrityRequirement": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "subAvailabilityImpact": "NONE", "vulnAvailabilityImpact": "NONE", "availabilityRequirement": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "subConfidentialityImpact": "LOW", "vulnConfidentialityImpact": "NONE", "confidentialityRequirement": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "vulnerabilityResponseEffort": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED"}}]}, "affected": [{"source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db", "affectedData": [{"cpes": ["cpe:2.3:a:lud:oaskit:*:*:*:*:*:elixir:*:*"], "repo": "https://github.com/lud/oaskit", "vendor": "lud", "modules": ["Elixir.Oaskit.ErrorHandler.Default"], "product": "oaskit", "versions": [{"status": "affected", "version": "0.1.0", "lessThan": "0.14.1", "versionType": "semver"}], "packageURL": "pkg:hex/oaskit", "packageName": "oaskit", "programFiles": ["lib/oaskit/error_handler/default.ex"], "collectionURL": "https://repo.hex.pm", "defaultStatus": "unaffected", "programRoutines": [{"name": "'Elixir.Oaskit.ErrorHandler.Default':format_reason/4"}, {"name": "'Elixir.Oaskit.ErrorHandler.Default':reason_to_html/1"}]}, {"cpes": ["cpe:2.3:a:lud:oaskit:*:*:*:*:*:elixir:*:*"], "repo": "https://github.com/lud/oaskit", "vendor": "lud", "modules": ["Elixir.Oaskit.ErrorHandler.Default"], "product": "oaskit", "versions": [{"status": "affected", "version": "552de8ca0ff60617bea58bcafa451892d61a161c", "lessThan": "b70c6b2eaf0b11bdd0bbb21b8a87dbb3d46918a1", "versionType": "git"}], "packageURL": "pkg:github/lud/oaskit", "packageName": "lud/oaskit", "programFiles": ["lib/oaskit/error_handler/default.ex"], "collectionURL": "https://github.com", "defaultStatus": "unaffected", "programRoutines": [{"name": "'Elixir.Oaskit.ErrorHandler.Default':format_reason/4"}, {"name": "'Elixir.Oaskit.ErrorHandler.Default':reason_to_html/1"}]}]}], "published": "2026-08-03T20:17:25.720", "references": [{"url": "https://cna.erlef.org/cves/CVE-2026-66296.html", "tags": ["Patch", "Third Party Advisory"], "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db"}, {"url": "https://github.com/lud/oaskit/commit/b70c6b2eaf0b11bdd0bbb21b8a87dbb3d46918a1", "tags": ["Patch"], "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db"}, {"url": "https://github.com/lud/oaskit/security/advisories/GHSA-h7xw-x8wr-xpcc", "tags": ["Exploit", "Vendor Advisory"], "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db"}, {"url": "https://osv.dev/vulnerability/EEF-CVE-2026-66296", "tags": ["Patch", "Third Party Advisory"], "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db"}, {"url": "https://github.com/lud/oaskit/security/advisories/GHSA-h7xw-x8wr-xpcc", "tags": ["Exploit", "Vendor Advisory"], "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0"}], "vulnStatus": "Analyzed", "weaknesses": [{"type": "Secondary", "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db", "description": [{"lang": "en", "value": "CWE-79"}]}], "descriptions": [{"lang": "en", "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."}], "lastModified": "2026-08-17T19:12:33.870", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:a:lud:oaskit:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "6A883114-0624-4C87-8FAF-B8C277AB8B61", "versionEndExcluding": "0.14.1", "versionStartIncluding": "0.1.0"}], "operator": "OR"}]}], "sourceIdentifier": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db"}