CVSS 3.1
7.1 highCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:LCVE-2021-43818
High (7.1). EPSS 2.7% chance of exploitation in the next 30 days. Fixed in lxml 4.6.5.
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.
Severity
- EPSS
- 2.7% chance of exploitation in the next 30 days; higher than 85% of CVEs (scores of 2026-10-31)
- CWEs
- CWE-79, CWE-74
- Published
- Modified
- Record from
- the NVD, synced
Affected
- debian:debian_linux
- fedoraproject:fedora
- lxml:lxml
- netapp:hci_storage_node_firmware
- netapp:solidfire
- netapp:solidfire_enterprise_sds
- oracle:communications_cloud_native_core_binding_support_function
- oracle:communications_cloud_native_core_network_exposure_function
- oracle:communications_cloud_native_core_policy
- oracle:http_server
- oracle:zfs_storage_appliance_kit
Packages (OSV)
| Advisory | Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|---|
| GHSA-55x5-fj6c-h6m8 | PyPI | lxml | <4.6.5 | 4.6.5 |
| PYSEC-2021-852 | PyPI | lxml | <4.6.5 | 4.6.5 |
References
- https://github.com/lxml/lxml/commit/12fa9669007180a7bb87d990c375cf91ca5b664a
- https://github.com/lxml/lxml/commit/a3eacbc0dcf1de1c822ec29fb7d090a4b1712a9c#diff-59130575b4fb2932c957db2922977d7d89afb0b2085357db1a14615a2fcad776
- https://github.com/lxml/lxml/commit/f2330237440df7e8f39c3ad1b1aa8852be3b27c0
- https://github.com/lxml/lxml/security/advisories/GHSA-55x5-fj6c-h6m8
- https://lists.debian.org/debian-lts-announce/2021/12/msg00037.html