{"id":"CVE-2026-28348","aliases":["GHSA-hw26-mmpg-fqfg","PYSEC-2026-2201"],"url":"https://o3.security/vulnerability/CVE-2026-28348","summary":"lxml_html_clean: CSS @import Filter Bypass via Unicode Escapes","details":"lxml_html_clean is a project for HTML cleaning functionalities copied from `lxml.html.clean`. Prior to version 0.4.4, the _has_sneaky_javascript() method strips backslashes before checking for dangerous CSS keywords. This causes CSS Unicode escape sequences to bypass the @import and expression() filters, allowing external CSS loading or XSS in older browsers. This issue has been patched in version 0.4.4.","published":"2026-03-05T19:49:26.385Z","modified":"2026-08-12T03:51:48.811998266Z","cvss":{"score":6.1,"severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N"},"epss":{"score":0.00228,"percentile":0.13353,"asOf":"2026-08-24"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"PyPI","name":"lxml-html-clean","fixedVersion":"0.4.4"}],"fix":{"url":"https://github.com/fedora-python/lxml_html_clean/commit/2ef732667ddbc74ea59847bcf24b75809aaeed3b","label":"fedora-python/lxml_html_clean@2ef7326"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/28xxx/CVE-2026-28348.json"},{"type":"ADVISORY","url":"https://github.com/fedora-python/lxml_html_clean/security/advisories/GHSA-hw26-mmpg-fqfg"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-28348"},{"type":"FIX","url":"https://github.com/fedora-python/lxml_html_clean/commit/2ef732667ddbc74ea59847bcf24b75809aaeed3b"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-12T03:51:48.811998266Z"}}