{"id":"CVE-2026-116695","aliases":["DEBIAN-CVE-2026-116695","EUVD-2026-111386","GHSA-pq4g-8rxf-4g29","OESA-2026-4724","OESA-2026-4725","OESA-2026-4726","OESA-2026-4760","UBUNTU-CVE-2026-116695"],"status":"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.","severity":{"version":"4.0","score":5.3,"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","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-12","score":0.00353,"percentile":0.29464,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-436"],"published":"2026-10-27T20:10:34Z","modified":"2026-11-11T12:45:03Z","fixes":[{"ecosystem":"RubyGems","package":"crass","fixed_in":["1.0.8"],"sources":["ghsa","osv"]},{"ecosystem":"Debian:14","package":"ruby-crass","fixed_in":["1.0.8-1"],"sources":["osv"]}],"affected":[{"source":"ghsa","ecosystem":"RubyGems","package":"crass","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"last_affected":"1.0.7"},{"fixed":"1.0.8"}]}]},{"source":"osv","ecosystem":"Debian:12","package":"ruby-crass","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.0.2-3","1.0.6-1","1.0.7-1","1.0.8-1"]},{"source":"osv","ecosystem":"Debian:13","package":"ruby-crass","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.0.6-1","1.0.7-1","1.0.8-1"]},{"source":"osv","ecosystem":"Debian:14","package":"ruby-crass","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.0.8-1"}]}],"versions":["1.0.6-1","1.0.7-1"]},{"source":"osv","ecosystem":"RubyGems","package":"crass","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.0.8"}]}],"versions":["0.0.1","0.0.2","0.1.0","0.2.0","0.2.1","1.0.0","1.0.1","1.0.2","1.0.3","1.0.4","1.0.5","1.0.6","1.0.7"]},{"source":"osv","ecosystem":"openEuler:24.03-LTS-SP3","package":"rubygem-crass","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.0.8-1.oe2403sp3"}]}],"bundled":4},{"source":"osv","ecosystem":"openEuler:22.03-LTS-SP4","package":"rubygem-crass","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.0.8-1.oe2203sp4"}]}],"bundled":4},{"source":"osv","ecosystem":"openEuler:24.03-LTS-SP1","package":"rubygem-crass","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.0.8-1.oe2403sp1"}]}],"bundled":4},{"source":"osv","ecosystem":"openEuler:24.03-LTS-SP4","package":"rubygem-crass","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.0.8-1.oe2403sp4"}]}],"bundled":4},{"source":"osv","ecosystem":"Ubuntu:16.04:LTS","package":"ruby-crass","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.0.2-2"]},{"source":"osv","ecosystem":"Ubuntu:18.04:LTS","package":"ruby-crass","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.0.2-2"]},{"source":"osv","ecosystem":"Ubuntu:20.04:LTS","package":"ruby-crass","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.0.2-2"]},{"source":"osv","ecosystem":"Ubuntu:22.04:LTS","package":"ruby-crass","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.0.2-2.1","1.0.2-3"]},{"source":"osv","ecosystem":"Ubuntu:24.04:LTS","package":"ruby-crass","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.0.2-3"]},{"source":"osv","ecosystem":"Ubuntu:26.10","package":"ruby-crass","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.0.6-1ubuntu1"]},{"source":"osv","ecosystem":"Ubuntu:26.04:LTS","package":"ruby-crass","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.0.6-1ubuntu1"]}],"products":[{"vendor":"rgrove","product":"crass"}],"references":[{"url":"https://github.com/rgrove/crass/security/advisories/GHSA-pq4g-8rxf-4g29","tags":["x_refsource_CONFIRM","advisory","web","report"]},{"url":"https://github.com/rgrove/crass/commit/689fc45c632fdf3803b2f4e844ffc9cca3b08f34","tags":["x_refsource_MISC","fix","web","report"]},{"url":"https://github.com/rgrove/crass/releases/tag/v1.0.8","tags":["x_refsource_MISC","web","report"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-116695","tags":["advisory"]},{"url":"https://github.com/rubysec/ruby-advisory-db/blob/master/gems/crass/GHSA-pq4g-8rxf-4g29.yml","tags":["web"]},{"url":"https://github.com/advisories/GHSA-pq4g-8rxf-4g29"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/116xxx/CVE-2026-116695.json","tags":["advisory"]},{"url":"https://security-tracker.debian.org/tracker/CVE-2026-116695","tags":["advisory"]},{"url":"https://github.com/rgrove/crass","tags":["package"]},{"url":"https://www.openeuler.org/zh/security/security-bulletins/detail/?id=openEuler-SA-2026-4724","tags":["advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-61846","tags":["advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-61847","tags":["advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-61848","tags":["advisory"]},{"url":"https://www.openeuler.org/zh/security/security-bulletins/detail/?id=openEuler-SA-2026-4725","tags":["advisory"]},{"url":"https://www.openeuler.org/zh/security/security-bulletins/detail/?id=openEuler-SA-2026-4726","tags":["advisory"]},{"url":"https://www.openeuler.org/zh/security/security-bulletins/detail/?id=openEuler-SA-2026-4760","tags":["advisory"]},{"url":"https://ubuntu.com/security/CVE-2026-116695","tags":["report"]},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-116695","tags":["report"]}],"sources":{"cve":[{"id":"CVE-2026-116695","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.","status":"published","published":"2026-10-27T20:10:34.01Z","modified":"2026-11-03T12:13:04.293Z","cvss":[{"version":"4.0","score":5.3,"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","level":"medium","assessor":"cna"}],"cwes":["CWE-436"],"updated_at":"2026-11-03T13:57:27.751141Z"}],"euvd":[{"id":"EUVD-2026-111386","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.","status":"published","published":"2026-10-27T20:10:34Z","modified":"2026-11-03T12:13:04Z","cvss":[{"version":"4.0","score":5.3,"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","level":"medium"}],"updated_at":"2026-11-03T13:54:42.043274Z"}],"ghsa":[{"id":"GHSA-pq4g-8rxf-4g29","title":"Crass: Incorrect tokenization of bad URLs enables CSS sanitizer bypass","description":"## Summary\n\nCrass's tokenizer didn't terminate a bad URL token at a `)` that followed an escaped backslash (`\\\\`). As a result, Crass consumed more input as part of the bad URL than a spec-compliant browser does. CSS sanitizers that parse untrusted CSS with Crass and re-emit it could be tricked into passing through declarations, style rules, or at-rules (including `@import`) that the sanitizer would otherwise have removed, but that a browser would then parse and apply.\n\n## Details\n\nWhile consuming the remnants of a bad URL (CSS Syntax Level 3, §4.3.15), Crass checked whether the *previously consumed* code point and the next code point formed a valid escape, in addition to checking the next two unconsumed code points. After an escaped backslash, the previously consumed code point is a backslash, so a following `)` was incorrectly treated as escaped and the bad URL token continued until the next unescaped `)` or the end of the input.\n\nBrowsers terminate the bad URL at that `)`, so everything Crass treated as part of the bad URL is live CSS to a browser.\n\nThis bug has existed in every released version of Crass.\n\n## Impact\n\nCrass by itself only mis-tokenizes input. The security impact is on CSS sanitizers that use Crass to make allow/deny decisions and then re-serialize the CSS. Exploitation requires a sanitizer that doesn't reject bad URL tokens wherever they occur. Confirmed examples (verified in Chromium against the sanitizers' output):\n\n- **Sanitize** (all versions through 7.0.0):\n  - In `Sanitize::CSS.properties` and `style` attributes, a bad URL inside a `[...]` or `(...)` block in the value of an allowlisted property can smuggle arbitrary declarations, such as `position: fixed` or a `background-image` URL with a disallowed protocol.\n  - In `Sanitize::CSS.stylesheet` and `\u003cstyle\u003e` elements, a bad URL in a selector can smuggle arbitrary style rules and at-rules, including `@import`.\n- **Loofah** (`Loofah::HTML5::Scrub.scrub_css`, used for `style` attributes), and therefore **rails-html-sanitizer** (`sanitize_css`, and `sanitize` when `style` is a permitted attribute): a bad URL inside an allowlisted function such as `calc()` or `rgb()` can smuggle declarations Loofah normally strips, such as `position: fixed` and `url()` values.\n\nSmuggled CSS can be used for UI redress (clickjacking or phishing overlays), loading attacker-controlled external resources, and, where rules or `@import` can be smuggled, CSS-based data exfiltration. This vulnerability doesn't allow script execution in modern browsers.\n\n## Patches\n\nFixed in Crass 1.0.8. Users of Sanitize, Loofah, rails-html-sanitizer, or any other library that uses Crass to sanitize CSS should upgrade Crass to 1.0.8 or later.\n\n## Workarounds\n\nThere are no practical workarounds other than upgrading. Rejecting any CSS input that contains the character sequence `\\\\` would block the known trigger, but this is a blunt measure and may reject legitimate CSS.\n\n## References\n\n- CSS Syntax Module Level 3, \"Consume the remnants of a bad url\": https://drafts.csswg.org/css-syntax-3/#consume-remnants-of-bad-url","status":"published","published":"2026-10-28T22:42:53Z","modified":"2026-10-28T22:42:53Z","cvss":[{"version":"4.0","score":5.3,"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","level":"medium"}],"cwes":["CWE-436"],"updated_at":"2026-11-02T14:41:39.926569Z"}],"nvd":[{"id":"CVE-2026-116695","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.","status":"published","published":"2026-10-27T21:18:05.473Z","modified":"2026-11-03T13:17:20.2Z","cvss":[{"version":"4.0","score":5.3,"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/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","level":"medium","assessor":"secondary"}],"cwes":["CWE-436"],"updated_at":"2026-11-03T18:16:46.478505Z"}],"osv":[{"id":"CVE-2026-116695","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.","status":"published","published":"2026-10-27T20:10:34.01Z","modified":"2026-11-05T02:30:20.144633713Z","cvss":[{"version":"4.0","score":5.3,"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","level":"medium"}],"cwes":["CWE-436"],"updated_at":"2026-11-07T03:08:01.156605Z"},{"id":"DEBIAN-CVE-2026-116695","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.","status":"published","published":"2026-10-27T21:18:05.473Z","modified":"2026-11-04T09:47:23.535666751Z","cvss":[{"version":"4.0","score":5.3,"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/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","level":"medium"}],"updated_at":"2026-11-04T10:05:57.467041Z"},{"id":"GHSA-pq4g-8rxf-4g29","title":"Crass: Incorrect tokenization of bad URLs enables CSS sanitizer bypass","description":"## Summary\n\nCrass's tokenizer didn't terminate a bad URL token at a `)` that followed an escaped backslash (`\\\\`). As a result, Crass consumed more input as part of the bad URL than a spec-compliant browser does. CSS sanitizers that parse untrusted CSS with Crass and re-emit it could be tricked into passing through declarations, style rules, or at-rules (including `@import`) that the sanitizer would otherwise have removed, but that a browser would then parse and apply.\n\n## Details\n\nWhile consuming the remnants of a bad URL (CSS Syntax Level 3, §4.3.15), Crass checked whether the *previously consumed* code point and the next code point formed a valid escape, in addition to checking the next two unconsumed code points. After an escaped backslash, the previously consumed code point is a backslash, so a following `)` was incorrectly treated as escaped and the bad URL token continued until the next unescaped `)` or the end of the input.\n\nBrowsers terminate the bad URL at that `)`, so everything Crass treated as part of the bad URL is live CSS to a browser.\n\nThis bug has existed in every released version of Crass.\n\n## Impact\n\nCrass by itself only mis-tokenizes input. The security impact is on CSS sanitizers that use Crass to make allow/deny decisions and then re-serialize the CSS. Exploitation requires a sanitizer that doesn't reject bad URL tokens wherever they occur. Confirmed examples (verified in Chromium against the sanitizers' output):\n\n- **Sanitize** (all versions through 7.0.0):\n  - In `Sanitize::CSS.properties` and `style` attributes, a bad URL inside a `[...]` or `(...)` block in the value of an allowlisted property can smuggle arbitrary declarations, such as `position: fixed` or a `background-image` URL with a disallowed protocol.\n  - In `Sanitize::CSS.stylesheet` and `\u003cstyle\u003e` elements, a bad URL in a selector can smuggle arbitrary style rules and at-rules, including `@import`.\n- **Loofah** (`Loofah::HTML5::Scrub.scrub_css`, used for `style` attributes), and therefore **rails-html-sanitizer** (`sanitize_css`, and `sanitize` when `style` is a permitted attribute): a bad URL inside an allowlisted function such as `calc()` or `rgb()` can smuggle declarations Loofah normally strips, such as `position: fixed` and `url()` values.\n\nSmuggled CSS can be used for UI redress (clickjacking or phishing overlays), loading attacker-controlled external resources, and, where rules or `@import` can be smuggled, CSS-based data exfiltration. This vulnerability doesn't allow script execution in modern browsers.\n\n## Patches\n\nFixed in Crass 1.0.8. Users of Sanitize, Loofah, rails-html-sanitizer, or any other library that uses Crass to sanitize CSS should upgrade Crass to 1.0.8 or later.\n\n## Workarounds\n\nThere are no practical workarounds other than upgrading. Rejecting any CSS input that contains the character sequence `\\\\` would block the known trigger, but this is a blunt measure and may reject legitimate CSS.\n\n## References\n\n- CSS Syntax Module Level 3, \"Consume the remnants of a bad url\": https://drafts.csswg.org/css-syntax-3/#consume-remnants-of-bad-url","status":"published","published":"2026-10-28T22:42:53Z","modified":"2026-10-28T23:00:04.150123033Z","cvss":[{"version":"4.0","score":5.3,"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","level":"medium"}],"cwes":["CWE-436"],"updated_at":"2026-11-02T15:46:53.700556Z"},{"id":"OESA-2026-4724","title":"rubygem-crass security update","description":"Crass is a pure Ruby CSS parser based on the CSS Syntax Level 3 spec.\r\n\r\nSecurity Fix(es):\n\nCrass 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.(CVE-2026-116695)\n\nCrass is a Ruby CSS parser that\u0026apos;s fully compliant with the CSS Syntax Level 3 specification. Prior to 1.0.7, Crass recursively parses `CSS simple blocks and functions` without a depth guard. An attacker-controlled CSS value containing deeply nested blocks or functions can recurse until Ruby raises `SystemStackError`: stack level too deep, or cause excessive memory usage. Version 1.0.7 adds a configurable depth limit with a conservative default. This issue is fixed in version 1.0.7.(CVE-2026-61846)\n\nCrass is a Ruby CSS parser that\u0026apos;s fully compliant with the CSS Syntax Level 3 specification. Prior to 1.0.7, when the `:preserve_comments` option is not enabled, which is the default, Crass discards CSS comments by recursively consuming the next token. An attacker-provided stylesheet containing a very large number of adjacent comments can cause excessive recursion and trigger a `SystemStackError`, denying service to the parsing application. Preserving comments avoids this recursive path. This issue is fixed in version 1.0.7.(CVE-2026-61847)\n\nCrass is a Ruby CSS parser that\u0026apos;s fully compliant with the CSS Syntax Level 3 specification. Prior to 1.0.7, when Crass parses input containing `non-ASCII characters`, inefficiencies in tracking the positions of `multi-byte characters` result in superlinear parsing time. An attacker-controlled CSS input consisting of many `non-ASCII characters` can therefore cause excessive CPU consumption and potentially denial of service. This issue is fixed in version 1.0.7.(CVE-2026-61848)","status":"published","published":"2026-11-04T13:54:55Z","modified":"2026-11-04T14:00:06.229931152Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high"}],"updated_at":"2026-11-04T14:10:46.921518Z"},{"id":"OESA-2026-4725","title":"rubygem-crass security update","description":"Crass is a pure Ruby CSS parser based on the CSS Syntax Level 3 spec.\r\n\r\nSecurity Fix(es):\n\nCrass 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.(CVE-2026-116695)\n\nCrass is a Ruby CSS parser that\u0026apos;s fully compliant with the CSS Syntax Level 3 specification. Prior to 1.0.7, Crass recursively parses `CSS simple blocks and functions` without a depth guard. An attacker-controlled CSS value containing deeply nested blocks or functions can recurse until Ruby raises `SystemStackError`: stack level too deep, or cause excessive memory usage. Version 1.0.7 adds a configurable depth limit with a conservative default. This issue is fixed in version 1.0.7.(CVE-2026-61846)\n\nCrass is a Ruby CSS parser that\u0026apos;s fully compliant with the CSS Syntax Level 3 specification. Prior to 1.0.7, when the `:preserve_comments` option is not enabled, which is the default, Crass discards CSS comments by recursively consuming the next token. An attacker-provided stylesheet containing a very large number of adjacent comments can cause excessive recursion and trigger a `SystemStackError`, denying service to the parsing application. Preserving comments avoids this recursive path. This issue is fixed in version 1.0.7.(CVE-2026-61847)\n\nCrass is a Ruby CSS parser that\u0026apos;s fully compliant with the CSS Syntax Level 3 specification. Prior to 1.0.7, when Crass parses input containing `non-ASCII characters`, inefficiencies in tracking the positions of `multi-byte characters` result in superlinear parsing time. An attacker-controlled CSS input consisting of many `non-ASCII characters` can therefore cause excessive CPU consumption and potentially denial of service. This issue is fixed in version 1.0.7.(CVE-2026-61848)","status":"published","published":"2026-11-04T13:54:56Z","modified":"2026-11-04T14:00:06.881270961Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high"}],"updated_at":"2026-11-04T14:10:46.921518Z"},{"id":"OESA-2026-4726","title":"rubygem-crass security update","description":"Crass is a pure Ruby CSS parser based on the CSS Syntax Level 3 spec.\r\n\r\nSecurity Fix(es):\n\nCrass 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.(CVE-2026-116695)\n\nCrass is a Ruby CSS parser that\u0026apos;s fully compliant with the CSS Syntax Level 3 specification. Prior to 1.0.7, Crass recursively parses `CSS simple blocks and functions` without a depth guard. An attacker-controlled CSS value containing deeply nested blocks or functions can recurse until Ruby raises `SystemStackError`: stack level too deep, or cause excessive memory usage. Version 1.0.7 adds a configurable depth limit with a conservative default. This issue is fixed in version 1.0.7.(CVE-2026-61846)\n\nCrass is a Ruby CSS parser that\u0026apos;s fully compliant with the CSS Syntax Level 3 specification. Prior to 1.0.7, when the `:preserve_comments` option is not enabled, which is the default, Crass discards CSS comments by recursively consuming the next token. An attacker-provided stylesheet containing a very large number of adjacent comments can cause excessive recursion and trigger a `SystemStackError`, denying service to the parsing application. Preserving comments avoids this recursive path. This issue is fixed in version 1.0.7.(CVE-2026-61847)\n\nCrass is a Ruby CSS parser that\u0026apos;s fully compliant with the CSS Syntax Level 3 specification. Prior to 1.0.7, when Crass parses input containing `non-ASCII characters`, inefficiencies in tracking the positions of `multi-byte characters` result in superlinear parsing time. An attacker-controlled CSS input consisting of many `non-ASCII characters` can therefore cause excessive CPU consumption and potentially denial of service. This issue is fixed in version 1.0.7.(CVE-2026-61848)","status":"published","published":"2026-11-04T13:54:57Z","modified":"2026-11-04T14:00:06.881129613Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high"}],"updated_at":"2026-11-04T14:10:46.921518Z"},{"id":"OESA-2026-4760","title":"rubygem-crass security update","description":"Crass is a pure Ruby CSS parser based on the CSS Syntax Level 3 spec.\r\n\r\nSecurity Fix(es):\n\nCrass 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.(CVE-2026-116695)\n\nCrass is a Ruby CSS parser that\u0026apos;s fully compliant with the CSS Syntax Level 3 specification. Prior to 1.0.7, Crass recursively parses `CSS simple blocks and functions` without a depth guard. An attacker-controlled CSS value containing deeply nested blocks or functions can recurse until Ruby raises `SystemStackError`: stack level too deep, or cause excessive memory usage. Version 1.0.7 adds a configurable depth limit with a conservative default. This issue is fixed in version 1.0.7.(CVE-2026-61846)\n\nCrass is a Ruby CSS parser that\u0026apos;s fully compliant with the CSS Syntax Level 3 specification. Prior to 1.0.7, when the `:preserve_comments` option is not enabled, which is the default, Crass discards CSS comments by recursively consuming the next token. An attacker-provided stylesheet containing a very large number of adjacent comments can cause excessive recursion and trigger a `SystemStackError`, denying service to the parsing application. Preserving comments avoids this recursive path. This issue is fixed in version 1.0.7.(CVE-2026-61847)\n\nCrass is a Ruby CSS parser that\u0026apos;s fully compliant with the CSS Syntax Level 3 specification. Prior to 1.0.7, when Crass parses input containing `non-ASCII characters`, inefficiencies in tracking the positions of `multi-byte characters` result in superlinear parsing time. An attacker-controlled CSS input consisting of many `non-ASCII characters` can therefore cause excessive CPU consumption and potentially denial of service. This issue is fixed in version 1.0.7.(CVE-2026-61848)","status":"published","published":"2026-11-11T12:25:53Z","modified":"2026-11-11T12:45:03.917829561Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high"}],"updated_at":"2026-11-11T13:08:46.301371Z"},{"id":"UBUNTU-CVE-2026-116695","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.","status":"published","published":"2026-10-27T21:18:00Z","modified":"2026-10-28T20:17:45.944025031Z","cvss":[{"version":"4.0","score":5.3,"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","level":"medium"}],"updated_at":"2026-11-02T16:56:00.081948Z"}]}}