VULNERABILITY INTELLIGENCE
CVE-2021-43818
CVSS score8.2 HIGH
EPSS probability2.66%
CISA KEVNot currently listed
Published2021-12-13
Last modified2026-06-17
CVSS vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:H/A:N
Description
lxml is a library for processing XML and HTML in the Python language. Prior to version 4.6.5, the HTML Cleaner in lxml.html lets certain crafted script content pass through, as well as script content in SVG files embedded using data URIs. Users that employ the HTML cleaner in a security relevant context should upgrade to lxml 4.6.5 to receive a patch. There are no known workarounds available.
Weakness classification
- CWE-74: Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')
- CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Primary references
- security-advisories@github.com — Patch, Third Party Advisory
- security-advisories@github.com — Patch, Third Party Advisory
- security-advisories@github.com — Patch, Third Party Advisory
- security-advisories@github.com — Third Party Advisory
- security-advisories@github.com — Mailing List, Third Party Advisory
- security-advisories@github.com
- security-advisories@github.com
- security-advisories@github.com
- security-advisories@github.com
- security-advisories@github.com — Third Party Advisory
- security-advisories@github.com — Third Party Advisory
- security-advisories@github.com — Third Party Advisory