01 Record
CVE-2021-43818
HTML Cleaner allows crafted and SVG embedded scripts to pass through
HighPUBLISHEDCNA: GitHub_M
CNA base score8.2 CVSS v3.xCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:H/A:N
02 Description
HTML Cleaner allows crafted and SVG embedded scripts to pass through
03 Exploitation and scoring
- Exploitation
- Assessed, none found. CISA's assessment recorded neither public exploit code nor evidence of exploitation when it was made.
- SSVC decision
- ExploitationnoneCISA recorded no public exploit code and no evidence of exploitation.
- AutomatablenoAt least one step from reconnaissance to exploitation cannot be reliably automated.
- Technical ImpactpartialSuccessful exploitation gives limited control of the vulnerable component.
- EPSS probability
- 2.66% probability of exploitation activity in the next 30 days.
- EPSS percentile
- Equal to or higher than the score of 85.2% of scored records. A rank, not a probability.
- NVD base score
- 7.1 (CVSS v3.x), scored by the NVD independently of the CNA.
- NVD CVSS vector
- CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:L
- NVD analysis status
- Modified. NVD last modified this record on 2026-06-17.
- Red Hat severity
- Moderate. Red Hat's rating for its own products, not a CVSS rating.
Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.
04 Metadata
- Published
- 2021-12-13 18:05Z4 YR AGO
- Last updated
- 2025-12-18 15:05Z10 MO AGO
- Reserved
- 2021-11-16
- Assigning CNA
- GitHub_M
- Record state
- PUBLISHED
- Severity
- High (CVSS 8.2)
- CNA CVSS vector
- CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:H/A:N
- Weaknesses
- Data version
- 5.2
- Document digest
- 511051bf76cfed5c55f3b806bc1ce50f914baf9ee82d64dfaeffaa22261f5671
05 Affected products
VendorProductVersionsPlatforms
06 References
- github.comhttps://github.com/lxml/lxml/security/advisories/GHSA-55x5-fj6c-h6m8
- github.comhttps://github.com/lxml/lxml/commit/12fa9669007180a7bb87d990c375cf91ca5b664a
- github.comhttps://github.com/lxml/lxml/commit/a3eacbc0dcf1de1c822ec29fb7d090a4b1712a9c#diff-59130575b4fb2932c957db2922977d7d89afb0b2085357db1a14615a2fcad776
- github.comhttps://github.com/lxml/lxml/commit/f2330237440df7e8f39c3ad1b1aa8852be3b27c0
- lists.fedoraproject.orgFEDORA-2021-6e8fb79f90https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ZQ4SPKJX3RRJK4UWA6FXCRHD2TVRQI44/
- lists.fedoraproject.orgFEDORA-2021-9f9e7c5c4fhttps://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/WZGNET2A4WGLSUXLBFYKNC5PXHQMI3I7/
- lists.debian.org[debian-lts-announce] 20211230 [SECURITY] [DLA 2871-1] lxml security updatehttps://lists.debian.org/debian-lts-announce/2021/12/msg00037.html
- www.debian.orgDSA-5043https://www.debian.org/security/2022/dsa-5043
- lists.fedoraproject.orgFEDORA-2022-96c79bf003https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TUIS2KE3HZ2AAQKXFLTJFZPP2IFHJTC7/
- lists.fedoraproject.orgFEDORA-2022-7129fbaeedhttps://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/V2XMOM5PFT6U5AAXY6EFNT5JZCKKHK2V/
- www.oracle.comhttps://www.oracle.com/security-alerts/cpuapr2022.html
- security.netapp.comhttps://security.netapp.com/advisory/ntap-20220107-0005/
- www.oracle.comhttps://www.oracle.com/security-alerts/cpujul2022.html
- security.gentoo.orgGLSA-202208-06https://security.gentoo.org/glsa/202208-06
07 Fixed in
AlmaLinux 8
- babel Fixed in 2.5.1-10.module_el8.6.0+2781+fed64c13
- python-nose-docs Fixed
A version is affected if any line below covers it.
- Affected before 1.3.7-31.module_el8.5.0+2569+5c5719bc
- Affected before 1.3.7-31.module_el8.6.0+2781+fed64c13
- python-psycopg2-doc Fixed in 2.7.5-7.module_el8.6.0+2781+fed64c13
- python-sqlalchemy-doc Fixed
A version is affected if any line below covers it.
- Affected before 1.3.2-2.module_el8.5.0+2569+5c5719bc
- Affected before 1.3.2-2.module_el8.6.0+2781+fed64c13
- python2 Fixed in 2.7.18-10.module_el8.6.0+2781+fed64c13.alma
- python2-Cython Fixed in 0.28.1-7.module_el8.6.0+2781+fed64c13
- python2-PyMySQL Fixed in 0.8.0-10.module_el8.6.0+2781+fed64c13
- python2-attrs Fixed in 17.4.0-10.module_el8.6.0+2781+fed64c13
- python2-babel Fixed in 2.5.1-10.module_el8.6.0+2781+fed64c13
- python2-backports Fixed in 1.0-16.module_el8.6.0+2781+fed64c13
- python2-backports-ssl_match_hostname Fixed in 3.5.0.1-12.module_el8.6.0+2781+fed64c13
- python2-bson Fixed in 3.7.0-1.module_el8.6.0+2781+fed64c13
- python2-chardet Fixed in 3.0.4-10.module_el8.6.0+2781+fed64c13
- python2-coverage Fixed in 4.5.1-4.module_el8.6.0+2781+fed64c13
- python2-debug Fixed in 2.7.18-10.module_el8.6.0+2781+fed64c13.alma
- python2-devel Fixed in 2.7.18-10.module_el8.6.0+2781+fed64c13.alma
- python2-dns Fixed in 1.15.0-10.module_el8.6.0+2781+fed64c13
- python2-docs Fixed in 2.7.16-2.module_el8.6.0+2781+fed64c13
- python2-docs-info Fixed in 2.7.16-2.module_el8.6.0+2781+fed64c13
- python2-docutils Fixed in 0.14-12.module_el8.6.0+2781+fed64c13
- python2-funcsigs Fixed in 1.0.2-13.module_el8.6.0+2781+fed64c13
- python2-idna Fixed in 2.5-7.module_el8.6.0+2781+fed64c13
- python2-ipaddress Fixed in 1.0.18-6.module_el8.6.0+2781+fed64c13
- python2-jinja2 Fixed in 2.10-9.module_el8.6.0+2781+fed64c13
- python2-libs Fixed in 2.7.18-10.module_el8.6.0+2781+fed64c13.alma
- python2-lxml Fixed in 4.2.3-6.module_el8.6.0+2781+fed64c13
- python2-markupsafe Fixed in 0.23-19.module_el8.6.0+2781+fed64c13
- python2-mock Fixed in 2.0.0-13.module_el8.6.0+2781+fed64c13
- python2-nose Fixed in 1.3.7-31.module_el8.6.0+2781+fed64c13
- python2-numpy Fixed in 1:1.14.2-16.module_el8.6.0+2781+fed64c13
- python2-numpy-doc Fixed in 1:1.14.2-16.module_el8.6.0+2781+fed64c13
- python2-numpy-f2py Fixed in 1:1.14.2-16.module_el8.6.0+2781+fed64c13
- python2-pip Fixed in 9.0.3-19.module_el8.6.0+2781+fed64c13
- python2-pip-wheel Fixed in 9.0.3-19.module_el8.6.0+2781+fed64c13
- python2-pluggy Fixed in 0.6.0-8.module_el8.6.0+2781+fed64c13
- python2-psycopg2 Fixed in 2.7.5-7.module_el8.6.0+2781+fed64c13
- python2-psycopg2-debug Fixed in 2.7.5-7.module_el8.6.0+2781+fed64c13
- python2-psycopg2-tests Fixed in 2.7.5-7.module_el8.6.0+2781+fed64c13
- python2-py Fixed in 1.5.3-6.module_el8.6.0+2781+fed64c13
- python2-pygments Fixed in 2.2.0-22.module_el8.6.0+2781+fed64c13
123 further packages in AlmaLinux 8 not shown (first 40 listed).
Source: AlmaLinux, AlmaLinux OS. Copyright (c) 2023 AlmaLinux OS. Licensed under MIT License. Received through OSV.dev. Reformatted by exploit.cc.
Arch Linux
- python-lxml Fixed in 4.6.5-1
Source: Arch Linux Security Tracker, the Arch Linux security team. Reformatted by exploit.cc.
CloudLinux 8
- babel Fixed in 2.5.1-10.module_el8.6.0+2781+fed64c13
- python-nose-docs Fixed
A version is affected if any line below covers it.
- Affected before 1.3.7-31.module_el8.5.0+2569+5c5719bc
- Affected before 1.3.7-31.module_el8.6.0+2781+fed64c13
- python-psycopg2-doc Fixed in 2.7.5-7.module_el8.6.0+2781+fed64c13
- python-sqlalchemy-doc Fixed
A version is affected if any line below covers it.
- Affected before 1.3.2-2.module_el8.5.0+2569+5c5719bc
- Affected before 1.3.2-2.module_el8.6.0+2781+fed64c13
- python2 Fixed in 2.7.18-10.module_el8.6.0+2781+fed64c13.alma
- python2-Cython Fixed in 0.28.1-7.module_el8.6.0+2781+fed64c13
- python2-PyMySQL Fixed in 0.8.0-10.module_el8.6.0+2781+fed64c13
- python2-attrs Fixed in 17.4.0-10.module_el8.6.0+2781+fed64c13
- python2-babel Fixed in 2.5.1-10.module_el8.6.0+2781+fed64c13
- python2-backports Fixed in 1.0-16.module_el8.6.0+2781+fed64c13
- python2-backports-ssl_match_hostname Fixed in 3.5.0.1-12.module_el8.6.0+2781+fed64c13
- python2-bson Fixed in 3.7.0-1.module_el8.6.0+2781+fed64c13
- python2-chardet Fixed in 3.0.4-10.module_el8.6.0+2781+fed64c13
- python2-coverage Fixed in 4.5.1-4.module_el8.6.0+2781+fed64c13
- python2-debug Fixed in 2.7.18-10.module_el8.6.0+2781+fed64c13.alma
- python2-devel Fixed in 2.7.18-10.module_el8.6.0+2781+fed64c13.alma
- python2-dns Fixed in 1.15.0-10.module_el8.6.0+2781+fed64c13
- python2-docs Fixed in 2.7.16-2.module_el8.6.0+2781+fed64c13
- python2-docs-info Fixed in 2.7.16-2.module_el8.6.0+2781+fed64c13
- python2-docutils Fixed in 0.14-12.module_el8.6.0+2781+fed64c13
- python2-funcsigs Fixed in 1.0.2-13.module_el8.6.0+2781+fed64c13
- python2-idna Fixed in 2.5-7.module_el8.6.0+2781+fed64c13
- python2-ipaddress Fixed in 1.0.18-6.module_el8.6.0+2781+fed64c13
- python2-jinja2 Fixed in 2.10-9.module_el8.6.0+2781+fed64c13
- python2-libs Fixed in 2.7.18-10.module_el8.6.0+2781+fed64c13.alma
- python2-lxml Fixed in 4.2.3-6.module_el8.6.0+2781+fed64c13
- python2-markupsafe Fixed in 0.23-19.module_el8.6.0+2781+fed64c13
- python2-mock Fixed in 2.0.0-13.module_el8.6.0+2781+fed64c13
- python2-nose Fixed in 1.3.7-31.module_el8.6.0+2781+fed64c13
- python2-numpy Fixed in 1:1.14.2-16.module_el8.6.0+2781+fed64c13
- python2-numpy-doc Fixed in 1:1.14.2-16.module_el8.6.0+2781+fed64c13
- python2-numpy-f2py Fixed in 1:1.14.2-16.module_el8.6.0+2781+fed64c13
- python2-pip Fixed in 9.0.3-19.module_el8.6.0+2781+fed64c13
- python2-pip-wheel Fixed in 9.0.3-19.module_el8.6.0+2781+fed64c13
- python2-pluggy Fixed in 0.6.0-8.module_el8.6.0+2781+fed64c13
- python2-psycopg2 Fixed in 2.7.5-7.module_el8.6.0+2781+fed64c13
- python2-psycopg2-debug Fixed in 2.7.5-7.module_el8.6.0+2781+fed64c13
- python2-psycopg2-tests Fixed in 2.7.5-7.module_el8.6.0+2781+fed64c13
- python2-py Fixed in 1.5.3-6.module_el8.6.0+2781+fed64c13
- python2-pygments Fixed in 2.2.0-22.module_el8.6.0+2781+fed64c13
123 further packages in CloudLinux 8 not shown (first 40 listed).
Derived from AlmaLinux 8. Partial coverage: only packages taken from AlmaLinux 8 are listed.
Source: CloudLinux errata, CloudLinux Inc. Derived from: AlmaLinux, AlmaLinux OS. Copyright (c) 2023 AlmaLinux OS. Licensed under MIT License. Received through OSV.dev. Reformatted by exploit.cc.
Debian 12
- lxml Fixed in 4.7.1-1
Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.
Debian 13
- lxml Fixed in 4.7.1-1
Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.
Debian 14
- lxml Fixed in 4.7.1-1
Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu 18.04 LTS
- lxml Fixed in 4.2.1-1ubuntu0.6
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu 20.04 LTS
- lxml Fixed in 4.5.0-1ubuntu0.5
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu 22.04 LTS
- lxml Fixed in 4.7.1-1
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu Pro 14.04 LTS
- lxml Fixed in 3.3.3-1ubuntu0.2+esm5Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu Pro 16.04 LTS
- lxml Fixed in 3.5.0-1ubuntu0.4+esm2Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
A release or ecosystem missing from this list has no record here. It may be unaffected or not covered by the source. Source notices and licences.