CVE catalog
CVE-2021-43818
lxml: CVE-2021-43818
- Severity
- High · CVSS 8.8
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:H/A:L - Published
- Source
- [NVD] · [CVE record]
- EPSS
- 2.66% · Oct 25, 2026
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.
Vulnerable and fixed packages
Distribution-reported package versions and fixes. These do not depend on matching against the OpenFactory package catalog.
| Distribution | Package | Release | Version | Status |
|---|---|---|---|---|
| Debian | lxml | sid | 6.1.3-1.1 | fixed |
| Debian | lxml | forky | 6.1.3-1 | fixed |
| Debian | lxml | trixie | 5.4.0-1 | fixed |
| Debian | lxml | bookworm | 4.9.2-1 | fixed |
| Debian | lxml | bookworm-security | 4.9.2-1+deb12u1 | fixed |
| Alpine | py3-lxml | 3.16 | 4.6.5-r0 | fixed |
| Alpine | py3-lxml | 3.17 | 4.6.5-r0 | fixed |
| Alpine | py3-lxml | 3.18 | 4.6.5-r0 | fixed |
| Alpine | py3-lxml | 3.19 | 4.6.5-r0 | fixed |
| Alpine | py3-lxml | 3.20 | 4.6.5-r0 | fixed |
| Alpine | py3-lxml | 3.21 | 4.6.5-r0 | fixed |
| Alpine | py3-lxml | 3.22 | 4.6.5-r0 | fixed |
| Alpine | py3-lxml | 3.23 | 4.6.5-r0 | fixed |
| Alpine | py3-lxml | 3.24 | 4.6.5-r0 | fixed |
| Ubuntu | lxml | pro | 3.4.4-1 | vulnerable |
| Ubuntu | lxml | pro | 3.5.0-1 | vulnerable |
| Ubuntu | lxml | pro | 3.5.0-1build1 | vulnerable |
| Ubuntu | lxml | pro | 3.5.0-1ubuntu0.1 | vulnerable |
| Ubuntu | lxml | pro | 3.5.0-1ubuntu0.2 | vulnerable |
| Ubuntu | lxml | pro | 3.5.0-1ubuntu0.3 | vulnerable |
| Ubuntu | lxml | pro | 3.5.0-1ubuntu0.4 | vulnerable |
| Ubuntu | lxml | pro | 3.5.0-1ubuntu0.4+esm2 | fixed |
| Ubuntu | lxml | 18.04 | 4.0.0-1 | vulnerable |
| Ubuntu | lxml | 18.04 | 4.1.0-1 | vulnerable |
| Ubuntu | lxml | 18.04 | 4.2.0-1 | vulnerable |
| Ubuntu | lxml | 18.04 | 4.2.1-1 | vulnerable |
| Ubuntu | lxml | 18.04 | 4.2.1-1ubuntu0.1 | vulnerable |
| Ubuntu | lxml | 18.04 | 4.2.1-1ubuntu0.2 | vulnerable |
| Ubuntu | lxml | 18.04 | 4.2.1-1ubuntu0.3 | vulnerable |
| Ubuntu | lxml | 18.04 | 4.2.1-1ubuntu0.4 | vulnerable |
| Ubuntu | lxml | 18.04 | 4.2.1-1ubuntu0.6 | fixed |
| Ubuntu | lxml | 20.04 | 4.4.1-1 | vulnerable |
| Ubuntu | lxml | 20.04 | 4.4.1-1build1 | vulnerable |
| Ubuntu | lxml | 20.04 | 4.4.2-1 | vulnerable |
| Ubuntu | lxml | 20.04 | 4.5.0-1 | vulnerable |
| Ubuntu | lxml | 20.04 | 4.5.0-1ubuntu0.1 | vulnerable |
| Ubuntu | lxml | 20.04 | 4.5.0-1ubuntu0.2 | vulnerable |
| Ubuntu | lxml | 20.04 | 4.5.0-1ubuntu0.3 | vulnerable |
| Ubuntu | lxml | 20.04 | 4.5.0-1ubuntu0.5 | fixed |
| Ubuntu | lxml | pro | 3.4.4-1 | vulnerable |
| Ubuntu | lxml | pro | 3.5.0-1 | vulnerable |
| Ubuntu | lxml | pro | 3.5.0-1build1 | vulnerable |
| Ubuntu | lxml | pro | 3.5.0-1ubuntu0.1 | vulnerable |
| Ubuntu | lxml | pro | 3.5.0-1ubuntu0.2 | vulnerable |
| Ubuntu | lxml | pro | 3.5.0-1ubuntu0.3 | vulnerable |
| Ubuntu | lxml | pro | 3.5.0-1ubuntu0.4 | vulnerable |
| Ubuntu | lxml | pro | 3.5.0-1ubuntu0.4+esm2 | fixed |
| Ubuntu | lxml | 18.04 | 4.0.0-1 | vulnerable |
| Ubuntu | lxml | 18.04 | 4.1.0-1 | vulnerable |
| Ubuntu | lxml | 18.04 | 4.2.0-1 | vulnerable |
| Ubuntu | lxml | 18.04 | 4.2.1-1 | vulnerable |
| Ubuntu | lxml | 18.04 | 4.2.1-1ubuntu0.1 | vulnerable |
| Ubuntu | lxml | 18.04 | 4.2.1-1ubuntu0.2 | vulnerable |
| Ubuntu | lxml | 18.04 | 4.2.1-1ubuntu0.3 | vulnerable |
| Ubuntu | lxml | 18.04 | 4.2.1-1ubuntu0.4 | vulnerable |
| Ubuntu | lxml | 18.04 | 4.2.1-1ubuntu0.6 | fixed |
| Ubuntu | lxml | 20.04 | 4.4.1-1 | vulnerable |
| Ubuntu | lxml | 20.04 | 4.4.1-1build1 | vulnerable |
| Ubuntu | lxml | 20.04 | 4.4.2-1 | vulnerable |
| Ubuntu | lxml | 20.04 | 4.5.0-1 | vulnerable |
| Ubuntu | lxml | 20.04 | 4.5.0-1ubuntu0.1 | vulnerable |
| Ubuntu | lxml | 20.04 | 4.5.0-1ubuntu0.2 | vulnerable |
| Ubuntu | lxml | 20.04 | 4.5.0-1ubuntu0.3 | vulnerable |
| Ubuntu | lxml | 20.04 | 4.5.0-1ubuntu0.5 | fixed |
| Ubuntu | lxml | 22.04 | 4.6.3+dfsg-0.1 | vulnerable |
| Ubuntu | lxml | 22.04 | 4.6.4-1 | vulnerable |
| Ubuntu | lxml | 22.04 | 4.6.4-1ubuntu1 | vulnerable |
| Ubuntu | lxml | 22.04 | 4.7.1-1 | fixed |
Fixed-version evidence
| Distribution | Package | Type | Release | Fixed version | Urgency | Origin | Bugs |
|---|---|---|---|---|---|---|---|
| Debian | lxml | source | sid | 4.7.1-1 | not yet assigned | Not reported | [1001885] |
| Debian | lxml | source | forky | 4.7.1-1 | not yet assigned | Not reported | [1001885] |
| Debian | lxml | source | trixie | 4.7.1-1 | not yet assigned | Not reported | [1001885] |
| Debian | lxml | source | bookworm | 4.7.1-1 | not yet assigned | Not reported | [1001885] |
| Alpine | py3-lxml | apk | 3.16 | 4.6.5-r0 | Not reported | ALPINE-CVE-2021-43818 | Not reported |
| Alpine | py3-lxml | apk | 3.17 | 4.6.5-r0 | Not reported | ALPINE-CVE-2021-43818 | Not reported |
| Alpine | py3-lxml | apk | 3.18 | 4.6.5-r0 | Not reported | ALPINE-CVE-2021-43818 | Not reported |
| Alpine | py3-lxml | apk | 3.19 | 4.6.5-r0 | Not reported | ALPINE-CVE-2021-43818 | Not reported |
| Alpine | py3-lxml | apk | 3.20 | 4.6.5-r0 | Not reported | ALPINE-CVE-2021-43818 | Not reported |
| Alpine | py3-lxml | apk | 3.21 | 4.6.5-r0 | Not reported | ALPINE-CVE-2021-43818 | Not reported |
| Alpine | py3-lxml | apk | 3.22 | 4.6.5-r0 | Not reported | ALPINE-CVE-2021-43818 | Not reported |
| Alpine | py3-lxml | apk | 3.23 | 4.6.5-r0 | Not reported | ALPINE-CVE-2021-43818 | Not reported |
| Alpine | py3-lxml | apk | 3.24 | 4.6.5-r0 | Not reported | ALPINE-CVE-2021-43818 | Not reported |
| Ubuntu | lxml | deb | pro | 3.5.0-1ubuntu0.4+esm2 | Not reported | USN-5225-1 | Not reported |
| Ubuntu | lxml | deb | 18.04 | 4.2.1-1ubuntu0.6 | Not reported | USN-5225-1 | Not reported |
| Ubuntu | lxml | deb | 20.04 | 4.5.0-1ubuntu0.5 | Not reported | USN-5225-1 | Not reported |
| Ubuntu | lxml | deb | pro | 3.5.0-1ubuntu0.4+esm2 | Not reported | UBUNTU-CVE-2021-43818 | Not reported |
| Ubuntu | lxml | deb | 18.04 | 4.2.1-1ubuntu0.6 | Not reported | UBUNTU-CVE-2021-43818 | Not reported |
| Ubuntu | lxml | deb | 20.04 | 4.5.0-1ubuntu0.5 | Not reported | UBUNTU-CVE-2021-43818 | Not reported |
| Ubuntu | lxml | deb | 22.04 | 4.7.1-1 | Not reported | UBUNTU-CVE-2021-43818 | Not reported |
OpenFactory catalog packages
[Debian 12 (Bookworm)]
- [python3-lxml]Fixed
Source package: [lxml]
Details (2)
4.9.2-1+b1· amd64 · bookwormFixed · Fixed:
4.7.1-1dsa · lxml · debian · bookworm; dsa · lxml · debian · 12
4.9.2-1+b1· arm64 · bookwormFixed · Fixed:
4.7.1-1dsa · lxml · debian · bookworm; dsa · lxml · debian · 12
- [python-lxml-doc]Fixed
Source package: [lxml]
Details (2)
4.9.2-1· all · bookwormFixed · Fixed:
4.7.1-1dsa · lxml · debian · bookworm; dsa · lxml · debian · 12
4.9.2-1· all · bookwormFixed · Fixed:
4.7.1-1dsa · lxml · debian · bookworm; dsa · lxml · debian · 12
[Debian 13 (Trixie)]
- [python3-lxml]Fixed
Source package: [lxml]
Details (2)
5.4.0-1· amd64 · trixieFixed · Fixed:
4.7.1-1dsa · lxml · debian · 13
5.4.0-1· arm64 · trixieFixed · Fixed:
4.7.1-1dsa · lxml · debian · 13
- [python-lxml-doc]Fixed
Source package: [lxml]
Details (2)
5.4.0-1· all · trixieFixed · Fixed:
4.7.1-1dsa · lxml · debian · 13
5.4.0-1· all · trixieFixed · Fixed:
4.7.1-1dsa · lxml · debian · 13
Observed:
References
- [https://ftp.suse.com/pub/projects/security/csaf/rhsa-2022_1821.json]
- [https://osv.dev/vulnerability/ALPINE-CVE-2021-43818]
- [https://osv.dev/vulnerability/DEBIAN-CVE-2021-43818]
- [https://osv.dev/vulnerability/DLA-2871-1]
- [https://osv.dev/vulnerability/DSA-5043-1]
- [https://osv.dev/vulnerability/UBUNTU-CVE-2021-43818]
- [https://osv.dev/vulnerability/USN-5225-1]
- [https://security-tracker.debian.org/tracker/CVE-2021-43818]
- [https://security.access.redhat.com/data/csaf/v2/vex/2021/cve-2021-43818.json]
- [https://wid.cert-bund.de/.well-known/csaf/white/2022/wid-sec-w-2022-0575.json]
[CERT-Bund public advisories] · [Debian Security Tracker] · [FIRST EPSS] · [OSV Package Vulnerability Database] · [Red Hat security advisories and VEX] · [SUSE security advisories and VEX]