{"api_version":"1","generated_at":"2026-11-12T23:45:47+00:00","cve":"CVE-2026-126207","urls":{"html":"https://cve.report/CVE-2026-126207","api":"https://cve.report/api/cve/CVE-2026-126207.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-126207","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-126207"},"summary":{"title":"Loofah: CSS url() sanitization bypass via escaped parentheses","description":"Loofah is a general library for manipulating and transforming HTML/XML documents and fragments, built on top of Nokogiri. Prior to 2.25.3, Loofah::HTML5::Scrub.scrub_css checks only the first parse of a style attribute, then rebuilds CSS with identifier escapes decoded so escaped parentheses, property names, comments, or quotes can become a live url() without a second safety check. An attacker can use list-style to make a viewer's browser request an attacker-chosen URL when content renders, or cursor to make the request on hover. The request can disclose the viewer's IP address, user agent, access timing, and access to internal-network hosts, but no script survives sanitization and the attacker cannot read the response. This issue is fixed in version 2.25.3.","state":"PUBLISHED","assigner":"GitHub_M","published_at":"2026-11-12 21:17:21","updated_at":"2026-11-12 22:09:39"},"problem_types":["CWE-180","CWE-184","CWE-180 CWE-180: Incorrect Behavior Order: Validate Before Canonicalize","CWE-184 CWE-184: Incomplete List of Disallowed Inputs"],"metrics":[{"version":"3.1","source":"security-advisories@github.com","type":"Secondary","score":"4.7","severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:N/A:N","data":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:N/A:N","baseScore":4.7,"baseSeverity":"MEDIUM","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"REQUIRED","scope":"CHANGED","confidentialityImpact":"LOW","integrityImpact":"NONE","availabilityImpact":"NONE"}},{"version":"3.1","source":"CNA","type":"DECLARED","score":"4.7","severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:N/A:N","data":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"NONE","baseScore":4.7,"baseSeverity":"MEDIUM","confidentialityImpact":"LOW","integrityImpact":"NONE","privilegesRequired":"NONE","scope":"CHANGED","userInteraction":"REQUIRED","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:N/A:N","version":"3.1"}}],"references":[{"url":"https://github.com/flavorjones/loofah/pull/324","name":"https://github.com/flavorjones/loofah/pull/324","refsource":"security-advisories@github.com","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://github.com/flavorjones/loofah/security/advisories/GHSA-m3x9-938q-5767","name":"https://github.com/flavorjones/loofah/security/advisories/GHSA-m3x9-938q-5767","refsource":"security-advisories@github.com","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://github.com/flavorjones/loofah/releases/tag/v2.25.3","name":"https://github.com/flavorjones/loofah/releases/tag/v2.25.3","refsource":"security-advisories@github.com","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://github.com/flavorjones/loofah/commit/b198a36e44c9c5408163ac50787825e8ca0b166b","name":"https://github.com/flavorjones/loofah/commit/b198a36e44c9c5408163ac50787825e8ca0b166b","refsource":"security-advisories@github.com","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-126207","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-126207","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"flavorjones","product":"loofah","version":"affected < 2.25.3","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":null,"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"product":"loofah","vendor":"flavorjones","versions":[{"status":"affected","version":"< 2.25.3"}]}],"descriptions":[{"lang":"en","value":"Loofah is a general library for manipulating and transforming HTML/XML documents and fragments, built on top of Nokogiri. Prior to 2.25.3, Loofah::HTML5::Scrub.scrub_css checks only the first parse of a style attribute, then rebuilds CSS with identifier escapes decoded so escaped parentheses, property names, comments, or quotes can become a live url() without a second safety check. An attacker can use list-style to make a viewer's browser request an attacker-chosen URL when content renders, or cursor to make the request on hover. The request can disclose the viewer's IP address, user agent, access timing, and access to internal-network hosts, but no script survives sanitization and the attacker cannot read the response. This issue is fixed in version 2.25.3."}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"NONE","baseScore":4.7,"baseSeverity":"MEDIUM","confidentialityImpact":"LOW","integrityImpact":"NONE","privilegesRequired":"NONE","scope":"CHANGED","userInteraction":"REQUIRED","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:N/A:N","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-180","description":"CWE-180: Incorrect Behavior Order: Validate Before Canonicalize","lang":"en","type":"CWE"}]},{"descriptions":[{"cweId":"CWE-184","description":"CWE-184: Incomplete List of Disallowed Inputs","lang":"en","type":"CWE"}]}],"providerMetadata":{"dateUpdated":"2026-11-12T20:53:55.553Z","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","shortName":"GitHub_M"},"references":[{"name":"https://github.com/flavorjones/loofah/security/advisories/GHSA-m3x9-938q-5767","tags":["x_refsource_CONFIRM"],"url":"https://github.com/flavorjones/loofah/security/advisories/GHSA-m3x9-938q-5767"},{"name":"https://github.com/flavorjones/loofah/pull/324","tags":["x_refsource_MISC"],"url":"https://github.com/flavorjones/loofah/pull/324"},{"name":"https://github.com/flavorjones/loofah/commit/b198a36e44c9c5408163ac50787825e8ca0b166b","tags":["x_refsource_MISC"],"url":"https://github.com/flavorjones/loofah/commit/b198a36e44c9c5408163ac50787825e8ca0b166b"},{"name":"https://github.com/flavorjones/loofah/releases/tag/v2.25.3","tags":["x_refsource_MISC"],"url":"https://github.com/flavorjones/loofah/releases/tag/v2.25.3"}],"source":{"advisory":"GHSA-m3x9-938q-5767","discovery":"UNKNOWN"},"title":"Loofah: CSS url() sanitization bypass via escaped parentheses"}},"cveMetadata":{"assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","assignerShortName":"GitHub_M","cveId":"CVE-2026-126207","datePublished":"2026-11-12T20:53:55.553Z","dateReserved":"2026-11-10T20:07:44.958Z","dateUpdated":"2026-11-12T20:53:55.553Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-11-12 21:17:21","lastModifiedDate":"2026-11-12 22:09:39","problem_types":["CWE-180","CWE-184","CWE-180 CWE-180: Incorrect Behavior Order: Validate Before Canonicalize","CWE-184 CWE-184: Incomplete List of Disallowed Inputs"],"metrics":{"cvssMetricV31":[{"source":"security-advisories@github.com","type":"Secondary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:N/A:N","baseScore":4.7,"baseSeverity":"MEDIUM","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"REQUIRED","scope":"CHANGED","confidentialityImpact":"LOW","integrityImpact":"NONE","availabilityImpact":"NONE"},"exploitabilityScore":2.8,"impactScore":1.4}]},"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"126207","Ordinal":"1","Title":"Loofah: CSS url() sanitization bypass via escaped parentheses","CVE":"CVE-2026-126207","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"126207","Ordinal":"1","NoteData":"Loofah is a general library for manipulating and transforming HTML/XML documents and fragments, built on top of Nokogiri. Prior to 2.25.3, Loofah::HTML5::Scrub.scrub_css checks only the first parse of a style attribute, then rebuilds CSS with identifier escapes decoded so escaped parentheses, property names, comments, or quotes can become a live url() without a second safety check. An attacker can use list-style to make a viewer's browser request an attacker-chosen URL when content renders, or cursor to make the request on hover. The request can disclose the viewer's IP address, user agent, access timing, and access to internal-network hosts, but no script survives sanitization and the attacker cannot read the response. This issue is fixed in version 2.25.3.","Type":"Description","Title":"Loofah: CSS url() sanitization bypass via escaped parentheses"}]}}}