{"id":"CVE-2023-36823","aliases":["GHSA-f5ww-cq3m-q3g7"],"url":"https://o3.security/vulnerability/CVE-2023-36823","summary":"Sanitize vulnerable to Cross-site Scripting via insufficient neutralization of `style` element content","details":"### Impact\n\nUsing carefully crafted input, an attacker may be able to sneak arbitrary HTML and CSS through Sanitize `>= 3.0.0, < 6.0.2` when Sanitize is configured to use the built-in \"relaxed\" config or when using a custom config that allows `style` elements and one or more CSS at-rules. This could result in XSS (cross-site scripting) or other undesired behavior when the malicious HTML and CSS are rendered in a browser.\n\n### Patches\n\nSanitize `>= 6.0.2` performs additional escaping of CSS in `style` element content, which fixes this issue.\n\n### Workarounds\n\nUsers who are unable to upgrade can prevent this issue by using a Sanitize config that doesn't allow `style` elements, using a Sanitize config that doesn't allow CSS at-rules, or by manually escaping the character sequence `</` as `<\\/` in `style` element content.\n\n### Credit\n\nThis issue was found by @cure53 during an audit of a project that uses Sanitize and was reported by one of that project's maintainers. Thank you!","published":"2023-07-06T15:06:00.509Z","modified":"2026-08-12T03:51:31.656544489Z","cvss":{"score":7.1,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:L"},"epss":null,"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"RubyGems","name":"sanitize","fixedVersion":"6.0.2"}],"fix":{"url":"https://github.com/rgrove/sanitize/commit/76ed46e6dc70820f38efe27de8dabd54dddb5220","label":"rgrove/sanitize@76ed46e"},"references":[{"type":"WEB","url":"https://github.com/rgrove/sanitize/releases/tag/v6.0.2"},{"type":"WEB","url":"https://lists.debian.org/debian-lts-announce/2023/11/msg00008.html"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/36xxx/CVE-2023-36823.json"},{"type":"ADVISORY","url":"https://github.com/rgrove/sanitize/security/advisories/GHSA-f5ww-cq3m-q3g7"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2023-36823"},{"type":"FIX","url":"https://github.com/rgrove/sanitize/commit/76ed46e6dc70820f38efe27de8dabd54dddb5220"},{"type":"PACKAGE","url":"https://github.com/rgrove/sanitize"},{"type":"WEB","url":"https://github.com/rubysec/ruby-advisory-db/blob/master/gems/sanitize/CVE-2023-36823.yml"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-12T03:51:31.656544489Z"}}