CVE-2026-66843

{"id": "CVE-2026-66843", "cveTags": [], "metrics": {"ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-66843", "role": "CISA Coordinator", "options": [{"exploitation": "none"}, {"automatable": "no"}, {"technicalImpact": "partial"}], "version": "2.0.3", "timestamp": "2026-08-06T15:40:41.682905Z"}}], "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": 2.3, "Automatable": "NOT_DEFINED", "attackVector": "NETWORK", "baseSeverity": "LOW", "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/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": "PASSIVE", "attackComplexity": "LOW", "attackRequirements": "PRESENT", "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:rrrene:html_sanitize_ex:*:*:*:*:*:*:*:*"], "repo": "https://github.com/rrrene/html_sanitize_ex", "vendor": "rrrene", "modules": ["Elixir.HtmlSanitizeEx.Scrubber.HTML5", "Elixir.HtmlSanitizeEx"], "product": "html_sanitize_ex", "versions": [{"status": "affected", "version": "0.3.1", "lessThan": "1.5.3", "versionType": "semver"}], "packageURL": "pkg:hex/html_sanitize_ex", "packageName": "html_sanitize_ex", "programFiles": ["lib/html_sanitize_ex/scrubber/html5.ex", "lib/html_sanitize_ex.ex"], "collectionURL": "https://repo.hex.pm", "defaultStatus": "unaffected", "programRoutines": [{"name": "'Elixir.HtmlSanitizeEx.Scrubber.HTML5':scrub_attribute/2"}, {"name": "'Elixir.HtmlSanitizeEx.Scrubber.HTML5':sanitize/1"}, {"name": "'Elixir.HtmlSanitizeEx':html5/1"}]}, {"cpes": ["cpe:2.3:a:rrrene:html_sanitize_ex:*:*:*:*:*:*:*:*"], "repo": "https://github.com/rrrene/html_sanitize_ex", "vendor": "rrrene", "modules": ["Elixir.HtmlSanitizeEx.Scrubber.HTML5", "Elixir.HtmlSanitizeEx"], "product": "html_sanitize_ex", "versions": [{"status": "affected", "version": "8976d64ea0b77d26093a94a43ec48a3978e8d028", "lessThan": "bec27fec4de99e40c68c4285a610e09e791a3eaf", "versionType": "git"}], "packageURL": "pkg:github/rrrene/html_sanitize_ex", "packageName": "rrrene/html_sanitize_ex", "programFiles": ["lib/html_sanitize_ex/scrubber/html5.ex", "lib/html_sanitize_ex.ex"], "collectionURL": "https://github.com", "defaultStatus": "unaffected", "programRoutines": [{"name": "'Elixir.HtmlSanitizeEx.Scrubber.HTML5':scrub_attribute/2"}, {"name": "'Elixir.HtmlSanitizeEx.Scrubber.HTML5':sanitize/1"}, {"name": "'Elixir.HtmlSanitizeEx':html5/1"}]}]}], "published": "2026-08-06T16:16:49.627", "references": [{"url": "https://cna.erlef.org/cves/CVE-2026-66843.html", "tags": ["Patch", "Third Party Advisory"], "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db"}, {"url": "https://github.com/rrrene/html_sanitize_ex/commit/bec27fec4de99e40c68c4285a610e09e791a3eaf", "tags": ["Patch"], "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db"}, {"url": "https://github.com/rrrene/html_sanitize_ex/security/advisories/GHSA-xmm9-jc22-rcgj", "tags": ["Broken Link"], "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db"}, {"url": "https://osv.dev/vulnerability/EEF-CVE-2026-66843", "tags": ["Patch", "Third Party Advisory"], "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db"}], "vulnStatus": "Analyzed", "weaknesses": [{"type": "Secondary", "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db", "description": [{"lang": "en", "value": "CWE-829"}]}], "descriptions": [{"lang": "en", "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."}], "lastModified": "2026-08-11T13:50:18.310", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:a:rrrene:htmlsanitizeex:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "DE85053C-AE84-4570-A90C-4D4CCD7A4BA3", "versionEndExcluding": "1.5.3", "versionStartIncluding": "0.3.1"}], "operator": "OR"}]}], "sourceIdentifier": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db"}