CVE-2021-43818
HTML Cleaner allows crafted and SVG embedded scripts to pass through
- State
- Published
- Severity
- 8.2 High
- Published
- Dec 13, 2021
- Updated
- Dec 18, 2025
- Reserved
- Nov 16, 2021
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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 3.1 | 8.2 High | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:H/A:N | GitHub_M |
Weaknesses
Affected Products
| Product | Versions |
|---|---|
lxmllxml |
|
References
- https://github.com/lxml/lxml/security/advisories/GHSA-55x5-fj6c-h6m8
- https://github.com/lxml/lxml/commit/12fa9669007180a7bb87d990c375cf91ca5b664a
- https://github.com/lxml/lxml/commit/a3eacbc0dcf1de1c822ec29fb7d090a4b1712a9c#diff-59130575b4fb2932c957db2922977d7d89afb0b2085357db1a14615a2fcad776
- https://github.com/lxml/lxml/commit/f2330237440df7e8f39c3ad1b1aa8852be3b27c0
- FEDORA-2021-6e8fb79f90vendor-advisory
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- DSA-5043vendor-advisory
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- https://www.oracle.com/security-alerts/cpuapr2022.html
- https://security.netapp.com/advisory/ntap-20220107-0005/
- https://www.oracle.com/security-alerts/cpujul2022.html
- GLSA-202208-06vendor-advisory
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