{"id":"CVE-2026-116695","state":"PUBLISHED","title":"Crass: Incorrect tokenization of bad URLs enables CSS sanitizer bypass","description":"Crass is a Ruby CSS parser that is compliant with the CSS Syntax Level 3 specification. Prior to 1.0.8, Crass incorrectly treats a closing parenthesis after an escaped backslash as escaped while consuming the remnants of a bad URL. Crass therefore keeps declarations, style rules, or at-rules inside a bad URL token even though a browser treats them as live CSS. A sanitizer that parses untrusted CSS with Crass and reserializes it without rejecting the bad URL can allow CSS used for UI redress, external resource loading, or CSS-based data exfiltration, but this issue does not enable script execution in modern browsers. This issue is fixed in version 1.0.8.","publishedAt":"2026-10-27T20:10:34.010Z","updatedAt":"2026-10-27T20:10:34.010Z","severity":{"score":5.3,"label":"Medium","version":"4.0","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N","source":"GitHub_M"},"assigner":"GitHub_M","products":["rgrove crass"],"affected":[{"vendor":"rgrove","product":"crass","versions":[{"version":"< 1.0.8","status":"affected"}]}],"references":["https://github.com/rgrove/crass/security/advisories/GHSA-pq4g-8rxf-4g29","https://github.com/rgrove/crass/commit/689fc45c632fdf3803b2f4e844ffc9cca3b08f34","https://github.com/rgrove/crass/releases/tag/v1.0.8"],"weaknesses":["CWE-436"],"ingestedAt":"2026-10-29T20:10:43.281Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/116xxx/CVE-2026-116695.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-116695","state":"PUBLISHED","datePublished":"2026-10-27T20:10:34.010Z","dateUpdated":"2026-10-27T20:10:34.010Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-10-26T20:00:59.831Z"},"containers":{"cna":{"title":"Crass: Incorrect tokenization of bad URLs enables CSS sanitizer bypass","descriptions":[{"lang":"en","value":"Crass is a Ruby CSS parser that is compliant with the CSS Syntax Level 3 specification. Prior to 1.0.8, Crass incorrectly treats a closing parenthesis after an escaped backslash as escaped while consuming the remnants of a bad URL. Crass therefore keeps declarations, style rules, or at-rules inside a bad URL token even though a browser treats them as live CSS. A sanitizer that parses untrusted CSS with Crass and reserializes it without rejecting the bad URL can allow CSS used for UI redress, external resource loading, or CSS-based data exfiltration, but this issue does not enable script execution in modern browsers. This issue is fixed in version 1.0.8."}],"affected":[{"vendor":"rgrove","product":"crass","versions":[{"version":"< 1.0.8","status":"affected"}]}],"references":[{"url":"https://github.com/rgrove/crass/security/advisories/GHSA-pq4g-8rxf-4g29","name":"https://github.com/rgrove/crass/security/advisories/GHSA-pq4g-8rxf-4g29","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/rgrove/crass/commit/689fc45c632fdf3803b2f4e844ffc9cca3b08f34","name":"https://github.com/rgrove/crass/commit/689fc45c632fdf3803b2f4e844ffc9cca3b08f34","tags":["x_refsource_MISC"]},{"url":"https://github.com/rgrove/crass/releases/tag/v1.0.8","name":"https://github.com/rgrove/crass/releases/tag/v1.0.8","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV4_0":{"attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"NONE","privilegesRequired":"NONE","userInteraction":"PASSIVE","vulnConfidentialityImpact":"NONE","vulnIntegrityImpact":"NONE","vulnAvailabilityImpact":"NONE","subConfidentialityImpact":"LOW","subIntegrityImpact":"LOW","subAvailabilityImpact":"NONE","baseScore":5.3,"baseSeverity":"MEDIUM","vectorString":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N","version":"4.0"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-436","lang":"en","description":"CWE-436: Interpretation Conflict","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-10-27T20:10:34.010Z"},"source":{"advisory":"GHSA-pq4g-8rxf-4g29","discovery":"UNKNOWN"}}}}}