What is CVE-2026-28350?

CVE-2026-28350 is a medium-severity vulnerability in Fedoralovespython Lxml HTML Clean, classified under Improper Encoding or Escaping of Output. CVSS score: 6.1/10. Published 2026-03-05.

How severe is CVE-2026-28350?

Medium severity. CVSS v3 base score is 6.1 out of 10.

Vulnerability in Fedoralovespython Lxml HTML Clean

CVE-2026-28350

lxml_html_clean is a project for HTML cleaning functionalities copied from `lxml.html.clean`. Prior to version 0.4.4, the <base> tag passes through the default Cleaner configuration. While page_structure=True removes html, head, and title tags, there is no specific handling for <base>, allowing an attacker to inject it and hijack relative links on the page. This issue has been patched in version 0.4.4.

EPSS: 0.003 (16.7th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N.

Affected products

Fedoralovespython Lxml_html_clean
Fedora-python Lxml_html_clean — versions < 0.4.4

Weakness classification (CWE)

CWE-116 — Improper Encoding or Escaping of Output

References

security-advisories@github.com (x_refsource_CONFIRM, Exploit, Vendor Advisory)
security-advisories@github.com (Patch, x_refsource_MISC)

Frequently asked questions

What is CVE-2026-28350?: CVE-2026-28350 is a medium-severity vulnerability in Fedoralovespython Lxml HTML Clean, classified under Improper Encoding or Escaping of Output. CVSS score: 6.1/10. Published 2026-03-05.
How severe is CVE-2026-28350?: Medium severity. CVSS v3 base score is 6.1 out of 10.